Best tire set up - 1973 Dart 440.

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74SwingerA

74SwingerA

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First off - sorry if this has been asked before, I did do a search but I am not seeing anything for my specific needs.

I am not really looking to make this a straight line beast but more an occasional track day/daily driver - I have my suspension set up chosen but I am a little confused if I should modify my wheel wells or not to fit fatter tires. I know wider rear tires = more grip = better hookup for drag racing but for track racing I am assuming that there comes a happy medium - fat tires offer better grip and breaking yet they can also create more weight, lessen turning radius, more road noise and you can hydroplane easier. Plus I am sure there is a lot of modification to the axles/suspension which means more added costs.

Knowing this, I know I will never reach full potential without choosing one path or another - daily driver or track car - but I would like to reach a happy medium. Should I tub the rear/front and install fatter tires or do you think something along the lines of 255's would work well for this application? I don't think so but I am novice and am trying to learn.

The engine is complete and will be running about 575 HP/537 FT LBS, a 440 relatively mildly built with no stroke or excessive cam lift. It has 11'' Wilwood disks and a hotchkins TVS upgrade coming in soon.

Well guys, give suggestions on rim/tire set-ups that work well for you.

Thank you,

Cody

Quick Edit - This is NOT for drag racing, I am from San Francisco and we have Laguna Seca and Sonoma Raceway nearby - I have a tuner (91 Supra Turbo, 420HP lots of mods) I run some days there but this is my first American Muscle car that will run track days.
 
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With a swinger and that kind of horsepower I would be inclined to at least use a 1/2” spring offset kit in the back so you could run 275’s in the rear. With the stock spring location you won’t be able to do more than 255’s, and even those may take some trimming depending on your body tolerances. The only way to go bigger than 275’s would be the full 3” spring relocation and mini-tub.

There are definitely cars out there that run really well on the strip with 275 sized tires, and if it’s mostly going to be a driver that would work, but I don’t think I’d settle for 255’s with that kind of power.
 
72bluenblue - I have heard great things about your knowledge from DAndy ART. I was thinking about doing a tub to accommodate 325's. What would you recommend I do to accomplish this? I wasn't thinking 255's would work out too well with nearly 600 HP. Enlighten me with your years of knowledge :D!
 
Well if you want to fit 325's you'll have to do the full 3" spring relocation to the frame rails, as well as a mini-tub. There's a bunch of different kits to do that, I think the US Cartool kit is probably the most straight forward. They locate the new spring boxes using the old mounts, so, lots easier for measuring and getting everything square. It also has the metal for extending the tubs. More expensive too. 67-75 A-body Mini tub and Rear Spring Relocation Combo Mopar Performance sells a kit as well, but their kit just has the spring boxes so you'd have to carefully square everything up, as well as come up with the sheet metal for the tubs. Cheaper, but more labor to set up correctly. https://www.summitracing.com/parts/dcc-4876558/overview/ Obviously both kits require a bunch of welding to install the spring boxes, move the perches, and mini-tub the stock wheel wells. And after all that you have to figure out your new rim offset. With 15" rims it means either getting custom made rims, or having the axle shortened so the width matches up with the backspace of the rims you want.

If you can live with 275's you can just use a 1/2" offset spring hanger/shackle kit from Dr. Diff, that's a bolt-in installation other than moving the spring perches on the axle. So the chassis remains stock basically. But the stock tubs limit you to a 275.

Just depends on what you're after.
 
Thank you again for this advice - Seeing as my father will be doing most of the metal fabrication work since this is his line of expertise (Body and fabrication) do you think it would be possible to shave the tubs vs doing a mini-tub to get a couple extra inches under there? If not then what tires would you recommend for the 275's? If I am going to go with the 275's then what would you recommend for the wheel size/spacing?

What about front wheel tires? How large can you go up front without expensive modifications to the control arms/strut rods?

Thank you very much,

Cody.
 
74SwingerA said:
72bluenblue - I have heard great things about your knowledge from DAndy ART...
Click to expand...

You heard right. 72blunblu knows his stuff!

So one thing you didn't ask about was wheel diameters...and I'd urge you to consider that as well.

If you said that you were building a dedicated strip car, a 15" slick would certainly do the job...but since you're indicating that you are looking at an optimal tire for a more well-rounded setup, you really have to take a look at modern diameters. 17" while, for now anyway, provide options for some modern rubber while still looking acceptable (IMO) on a classic body style...and you might be able to get comparable performance out of a narrower modern tire and avoid major surgery on your chassis.

Unless you're secretly Parnelli Jones himself, odds are that a 255/45/17 (~25.5" tall) or 255/50/17 (~27" tall) summer performance tire (which would fit in your stock wheelwells/spring locations with the proper offset wheels) would provide more than enough traction than you or your chassis could ever use effectively.

Meanwhile, non-drag tires in 15" diameter are limited to old tech/no-season (aka all season) options. If all-around performance is your goal, skip 15s.

co_extremecontact_spt_pdpcrop.jpg
 
Definitely not Parnelli Jones - though I have had a couple fast laps in the Supra I am not hitting 1:10 lap times at Laguna Seca haha. This is pure hobby and the only thing I am worried about is out-of-corner acceleration issues where the car over-steers from excessive loss of grip on the rear end. I know that these older cars can be lively and it's very much a concern.

I have been looking into a taller tire to be honest but I also want there to be adequate tire-to-road contact so sizing is very important. I am thinking maybe running some Billet Specialty Wheels 17 X 10.5 and some 275 40R17 BFGoodwrench G-ForceSport comp 2 Ultra-performance summer tires. I think that this is a good set-up, though I am really open to wheel idea's but I think I like the idea of a fatter tire.
 
You won't get anything larger than 275's into the stock tubs in the back. Wall-to-wall the stock wheel wells on a Swinger are ~12.5" at the absolute widest point, and realistically they taper down to about ~12" just a couple inches above the top of the wheel openings. Section width on most 275's is 11". Even if you completely removed the quarter lip (which I don't recommend) you still wouldn't have enough room to run anything much bigger than a 275. The 275's themselves are a stretch, most find they have to do some trimming on the quarter lip depending on the body tolerances. And since the body tolerances vary by as much as a 1/4" normally, you can't really count on having enough room to go bigger than 275.

As for the fronts, it depends what diameter rims you want to use. If you want to stay with 17's, 255 is about as wide as you can go. The reason for that is that 17" rims will still interfere with the outer tie rod between 5.6" and 6" of backspace, depending on the design of the rim itself. That's using the 73+ mopar disks, if you have wilwoods you'll have to check the track width changes and adjust those numbers. I know of one car that ran 275/40/17's up front using 17x9" Cobra R rims with a 6" backspace, but the clearance on that car to the outer tie rod was marginal. And that's the most I've heard for backspace on a 17" rim. The OE mustang bullit rims, for example, run out of clearance at 5.6", which isn't enough to run 275's on a 17x9". 255's will work on a 17x9" with 5.6" of backspace up front, they'd be in the same spot to the fender as my 275's. You won't get 17x10.5's up front, and actually I don't think you'll do it in the back either. Remember a 10.5" wide rim is actually 11.5" wide outside lip to outside lip. Not enough clearance there, not with the stock tubs anyway.

If you go up to 18" diameter wheels, you can run 275's up front. It's pretty tight, I did it for awhile on my Duster without rolling the fender lips but I've since rolled them because of my ride height. With the 18" rims the outer tie rod actually fits inside the rim so you don't have to worry about clearance there. On my car I found I did need tubular UCA's to clear my 18x9's up front, the rims would hit the stock UCA's with the steering at full lock and the suspension on the bump stops. So, with 18's and tubular UCA's the only limits are the frame rail and the fender, and that gets you to a 275 in the front. A few people are running 275/35/18's up front now, I do it on an 18x9" with about 27mm of offset (6.1" backspace). Again that's for a 73+ disk brake track width, my wheels are actually a +35 offset but I use Dr. Diff brakes and a 3mm spacer. I know peter, GmachineDartGT, is running 275/35/18's all the way around on his '71 Swinger now, also on 18x9's. He has a 1/2" spring offset and trimmed quarter lips in the back on his car. I know an 18x9.5" would work all the way around, maybe 18x10's but that might get interesting again on the UCA's in the front depending on which ones you had. And, that would change the tire width again, you'd be really maxed out. The fact that Peter and I are both using 18x9's means the 275's we're running are squeezed a little. Not much, but there's not much clearance either.

GmachineDartGT's '71 Dart
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I run 18x9's and 18x10's on my Duster, with 275/35/18's up front and 295/35/18's out back. But the sport body cars (Dusters, Demons, Dart Sports, and even Barracuda's) have an extra inch in the rear wheel tubs than the Dart body does, so with a 1/2" offset and a quarter lip trim I can manage 295's without a mini-tub. A swinger can't.
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72blunblu - Thank you so much for this! Is the purple Dart and the orange Charger yours as well? I am really digging the Sport too - has a real back-yard build look to it. It really looks like a scrapper (Fighter, not junkyard). I think it's really cool - sorta like the Monte Carlo from Tokyo Drift.

Going off what you're saying is it is a lot of work for a couple more inches in tire width (above 275). I love the way the 275's look and I think that they would provide better ground contact giving better grip but if you think the 255's would be better then I am willing to go to them. If you have a list of parts needed to run the 18 inch 275's front and rear then I am willing to consider it. Yes I am running, or will be once installed, wilwood 12'' disks and four pot calipers. My father and I will be tackling most the body work, since I really trust no one else to do this stuff. Dad does concours cars for Kevin Kay Restorations, cars that have won concours showings, so we can basically do anything in his shop fabrication wise. I would just need a list of things to do, and if you have preferences, parts you guys like to use.

So if I am correct I would need to probably roll the front lip of the Swinger, I have bought QA1 Tubular lower/upper control arms - QA1 52301: Tubular Upper Control Arms 1973-76 Mopar A-Body | JEGS - Do you still recommend that I offset the spring perches with the Dr.Diff kit? Would I need to roll the rear lip as well to fit the 18x9 as well?

Brake's I've ordered - https://www.summitracing.com/parts/wil-140-11019-d/overview/year/1973/make/dodge/model/dart front and https://www.summitracing.com/parts/wil-140-10767-d/overview/year/1973/make/dodge/model/dart - Rear.

Thank you everyone for the help.

Cody
 
74SwingerA said:
72blunblu - Thank you so much for this! Is the purple Dart and the orange Charger yours as well? I am really digging the Sport too - has a real back-yard build look to it. It really looks like a scrapper (Fighter, not junkyard). I think it's really cool - sorta like the Monte Carlo from Tokyo Drift.

Going off what you're saying is it is a lot of work for a couple more inches in tire width (above 275). I love the way the 275's look and I think that they would provide better ground contact giving better grip but if you think the 255's would be better then I am willing to go to them. If you have a list of parts needed to run the 18 inch 275's front and rear then I am willing to consider it. Yes I am running, or will be once installed, wilwood 12'' disks and four pot calipers. My father and I will be tackling most the body work, since I really trust no one else to do this stuff. Dad does concours cars for Kevin Kay Restorations, cars that have won concours showings, so we can basically do anything in his shop fabrication wise. I would just need a list of things to do, and if you have preferences, parts you guys like to use.

So if I am correct I would need to probably roll the front lip of the Swinger, I have bought QA1 Tubular lower/upper control arms - QA1 52301: Tubular Upper Control Arms 1973-76 Mopar A-Body | JEGS - Do you still recommend that I offset the spring perches with the Dr.Diff kit? Would I need to roll the rear lip as well to fit the 18x9 as well?

Brake's I've ordered - https://www.summitracing.com/parts/wil-140-11019-d/overview/year/1973/make/dodge/model/dart front and https://www.summitracing.com/parts/wil-140-10767-d/overview/year/1973/make/dodge/model/dart - Rear.

Thank you everyone for the help.

Cody
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The purple dart belongs to Peter Bergman. He runs Bergman Autocraft, which sells some really nice parts like the Borgeson power steering conversion, Delrin LCA bushings. and SPC adjustable UCA's. Plus some other stuff I left out. He's member @GMachineDartGT on here, I just linked his most recent picture to show the 275's on a Dart. Not sure if the orange Challenger is his or not, it's definitely not mine.

Yeah my Duster turned Demon tribute is literally a backyard build, I do all the work myself and have a garage in my backyard. :D It's also my daily driver, and the newest model year car I own. So it looks in progress because it still is. One of these days I'll get it all one color, but probably not anytime soon. My build thread on the Duster is here My "new" '74 Duster- or why I need a project like a hole in the head

As for the 255's or 275's, it's up to you. They'll both fit, but the 255's would work on a 17" rim. The 275's will need to be on an 18" to run the kind of backspace you'd need to clear the fenders. Peter has run both 255's and 275's, so maybe he'll comment on the differences now that I've tagged him in this thread. For the 275's it would be best if you rolled the fender and quarter lips. It might not be absolutely necessary depending on how your rim selection and backspacing works out, but I wouldn't plan on 275's if you absolutely don't want to roll the fenders and quarters.

As far as a list of parts, you don't really need much just to run the 275's. You'd need 18x9 or 18x9.5" rims, the QA1 tubular UCA's you already ordered for the front should work, and you'd need the 1/2" spring offset from Dr. Diff in the back (which will require moving the spring perches on the rear axle). You'll probably want to roll the fenders and quarters. But that's all you really NEED to have. Now, if you want to make best use of a nice set of grippy 275's, you'll need larger torsion bars (1.03" or bigger), better shocks (bilstein or hotchkis), decent rear springs, sway bars, etc. And you'll probably want at least some chassis stiffening, subframe connectors, torque boxes, etc. You can go all kinds of crazy, just depends on how serious you want to get and how much money you have to spend.

I have all of my parts listed in my build thread, but a quick summary on my '74 goes like this....

Front suspension:
  • 1.12" torsion bars from Firm Feel: $355
  • Bergman Autocraft SPC UCA's:$395
  • Howe Racing upper ball joints #22320: $130
  • Moog lower ball joints:$80
  • QA1 LCA's #52307: $375
  • Bergman Autocraft Delrin LCA bushings: $85
  • Firm Feel greasable LCA pins: $100
  • Hotchkis Shocks #79020015: $470
  • Hellwig 55905 front bar: $140
  • Flaming River 16:1 steering box #FR1540: $635
  • QA1 tie rod sleeves #52325: $50
  • Moog tie rods (all): $60
  • Moog pitman and idler arms: $80
  • Adjustable QA1 strut rods #52311 : $215

Rear Suspension:
  • Hellwig 6908 rear bar: $200 (this is the Ebody bar I run with my B-body rear axle)
  • AFCO 20231M springs: $320 (no longer available. Closest available are mopar oval track springs, P4529414, $215)
  • AFCO leaf spring sliders 20236S: $200
  • Dr. Diff 1/2" spring offset:$150
  • Leaf spring perches: $15

Front suspension: 3,170
Rear suspension total: 780
Total: $3,950

In addition to that stuff, I have a 13" Cobra style brake kit from Dr. Diff Mopar Cobra-style 13" Front Disc Brake Kit (Stage 3), the Enkei RPF1's in 18x9" +35mm and 18x10 +38mm (this is with a B body 8 3/4, not an A body so higher offset), 275/35/18 and 295/35/18 BFG KDW2's, homemade tubular subframe connectors, US Cartool torque boxes, J-bars (firewall to front frame rail, tying in shock mounts), tubular lower radiator support brace, and a fully seam welded and gusseted K frame. Plus rolled front fenders and trimmed rear quarter lips. And some other stuff I'm sure I've forgotten, it's all pretty much in my build thread.
 
Your car seems awesome Blu - I don't know I kinda like the cream/black. I really think it's cool but I get wanting to match the color PLUS have the color of your choice. Thank you for tagging GmachineDartGT too - I am trying my best to make this right the first time.

Thank you very much for this list of good - It pretty much follows what I have ordered, hotchkins sways, strut rods, leaf's, subframe connectors, QA1 UCA and LCA and strut rods, Fully polly bushings, better ball joints, proforged control arm shafts and idler arm, Firm Feel K-frame reinforcement kit, Firm Feel Bilstein shocks, 1.12 DIA torsion bars from Firm Feel, and I am getting that Dr. Diff relocation kit you recommended. So far I spent about $3500 but I am sure I will have more into it, I have no idea what steering box or ratio I want to go and I am sure there will unexpected expenses as well. How do you like your steering box and what did you do for your radiator mounts? Do you like US Cartool for their stiffened chassis kit? Would you chose a 8 3/4 or Dana 60, do you think the 8 1/4 can be utilized if done correctly?

I am jumping into your thread right now!
 
I like the fast ratio, 16:1 manual steering. With 275's up front and +6.75* of caster it doesn't make for much fun if you're parallel parking, but once you're going 10mph or so it's awesome. That's the same ratio as the stock power steering, just without the boost. For power steering I would just convert to the Borgeson box Peter sells, it's 14:1 and is significantly smaller and lighter than the stock power steering box.

Radiator mounts? I have a Champion 26" radiator, it's made to fit an A-body. My car had a 22" radiator originally though so I just drilled a couple of holes and welded nuts onto the back of the radiator support, just like stock.

I do like US Cartool's stiffening parts, except for the subframe connectors. They look great and they're strong, but they're a pain in the butt to install compared to a tubular set. But if you have the Hotchkis one's I wouldn't worry about it, those are good. But the US Cartool torque boxes, front inner fender braces, and radiator support brace are nice. I installed pretty much everything US Cartool makes on my '71 GT, the USCT subframes are the only part I wouldn't do again. The radiator support brace probably isn't as strong as the full tubular brace I installed on my Duster, but it looks more stock than the big round tube I've got. Same for the inner fender/shock mount braces. The J bars I have on the Duster are probably stronger, but the US Cartool pieces aren't nearly as obvious or in the way. And they do a lot to add stiffness to the chassis.

For the rear axle, I think with 575 hp I'd just go straight to a Dana 60. I don't think I'd use the 8.25" with that kind of power. It might be ok for just a street driven car, but with any kind of track time I don't think I'd mess with it. The 8 3/4 would work, but if you don't have one already the cost won't be all that much less than a Dana 60 by the time you've built a solid 8 3/4 up. I just ordered a new 3rd member for my upcoming T56 swap, with a new housing, HD adjusters, 1350 yoke, Truetrac and 4.30 gears it was $1375 from Dr. Diff. Good price considering it's a new 3rd member. But I already have the B-body 8 3/4 installed in my car, axles, etc. If you didn't have an 8 3/4, and for a Swinger I'd want something close to the original A-body width, you'd either have to buy an A-body housing (pricey!), or find a 65-67 B body housing. Or have one shortened with a custom width. Rather than do all that I'd just have Dr. Diff built a new strange S60 and have it set up exactly how you want it for perches and overall width. Might cost a little more all said and done, but maybe not depending the axles and stuff for the 8 3/4.
 
Checking out that Diff now - The measurements look a little complicated but I am sure I can ask around before I order. Thank you for your help and suggestions, I've really appreciated it. Tell me about this T56 swap, you have me VERY intrigued.
 
The measurements for the rear axle aren’t bad, my suggestion would be is that if you’re going to order one or use a custom width to pick your wheels and tires first, then get the axle width you need to make that work. BBP A-bodies with the stock width rear axle don’t usually end up with the same wheel offset front and rear, so, I would try to set the rear axle width up so I could use the same wheels all the way around. That way you can rotate tires and only have to find one spec for your wheels.

The T56 swap is pretty involved. Using all new parts the price tag is close to $6k, and even after that there’s still some significant fabrication that has to happen. New trans tunnel, a new upper crossmember has to be fabricated, and a lower mount. ToddRon restorations makes an upper and lower crossmember, but it’s pricey (~$700) and is set up for the Ford T56. A few member have done it successfully, it’s a great transmission and it works great, but it’s not a small undertaking.
 
Hm, well, yeah I figured it would be but what are you looking to get out of it? Why spend 6K + on a this one individual car vs your challenger that you've been planning on doing body work for haha! That would SURELY cover it XD!! I am just trying to pick your brain, after all it's your money : P.

So I would want to have my wheels selected first then order the custom rear end - What measurements would I need to make on the wheels in order to have a proper offset? I am playing around with wheel options right now but I will probably order this rear end in the coming month or two.
 
74SwingerA said:
Hm, well, yeah I figured it would be but what are you looking to get out of it? Why spend 6K + on a this one individual car vs your challenger that you've been planning on doing body work for haha! That would SURELY cover it XD!! I am just trying to pick your brain, after all it's your money : P.

So I would want to have my wheels selected first then order the custom rear end - What measurements would I need to make on the wheels in order to have a proper offset? I am playing around with wheel options right now but I will probably order this rear end in the coming month or two.
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Overdrive is a no brainer. My cam wants 3.91 gears, but my commute needs 75mph freeway speeds. So, overdrive. I've been making it work with 3.55's, but, even with an 833 that has a 3.09 first gear with 26" tall tires my take off is not great.

And pretty much any overdrive option is going to cost several thousand dollars. Honestly Gear Vendors at ~$3k plus installation is probably one of the cheapest ways to go. But then you still have the 833, which I don't have to say doesn't shift as nicely as a modern manual trans. Any of the manual transmission kits, 5 speeds anyway, run close to $5k for a complete install once everything is said and done. And they still require some tunnel and crossmember work. So, why NOT a 6 speed? Not really that much more money. More fabrication, but you get two overdrive gears. And I'm talking about all new parts too. You can make it happen cheaper with a used T56, but, that's not what I wanted to do. I mean, 4.30 gears, 75 mph at 2,600 rpm and a theoretical 170 mph top speed? I can run autoX in second gear and still have enough legs to go as fast as I want on a full road course, and cruise happily on the freeway.

As for the Challenger, I do all my own bodywork too, so, that's free besides materials, but I buy Summit paint because, drivers. And I have all the stuff for the T56 swap already purchased, so, it's not going to interfere with the quarters I need to buy for my Challenger. I already have all the other body parts, including the roof. I've been sitting on most of the T56 parts for over a year, as a lot of the folks following my build thread like to point out. I just have to stop driving my Duster long enough to do the swap.

For the rear axle and wheels, you need to measure from the outside edge of your springs to the quarter lip. With the 1/2" spring offset that should be close to 12". Then you need to plan for at least a 1/2" of clearance to the quarter lip. From there, it's all math using the specs of the wheels you want. Using the backspace, front space, and tire section width to figure out where the wheel mounting surface needs to be, which will tell you the width of the rear axle.

Like this guy here
18x9offsetspecs.jpg


So, using this wheel for an example, with a 275/35/18, and assuming you really got 12" from spring to quarter lip (maybe after the roll). Section width is 11", so the section width overhangs the wheel by a 1/2" on either side (worst case). 1/2" offset springs should be 42" center to center on the perches, springs are 2.5" wide, so, outside to outside on the springs is 44.5". We'll split the 1" of clearance in the wheel tub evenly, so, 1/2" to the springs too. So, now the axle is 45.5" wide. Add the tire overhanging the rim (+1"), 46.5. Add the backspace (+12"), 58.5". So, if you want to run 18x9's with a 25mm offset (6" backspace), with 275's then you get a wheel mount to wheel mount width of 58.5". Want an 18x9.5" in a +25? Well, now the backspace is 6.25, so, the axle has to be 59" wheel mount to wheel mount.

And then you can check the front space too as a check on your math. So, back to the 18x9's. WM to WM is 58.5". Spring to wheel mount is 7" (6" backspace + .5" tire + .5" space). Front space is 4", plus a 1/2" of tire, so 4.5". We had 12" spring to quarter, so, 12-7" = 5, and we have a 1/2" of clearance still. :D

How's it compare to real life? Well my Duster has a 68-70 B-body 8 3/4, which is 60.125" wide WM to WM. I run 295's on 18x10's with a 7" backspace, and I have the same 1/2" spring offset. So, start with the same 44.5" on the springs, add 14" for the backspace, 58.5. Add an inch for the section width (1/2" on each side), 59.5". Running out of clearance, that's only 5/8 left with the 60.125" axle width. But if I told you my springs only have about 3/8" clearance, and my actual real life tires overhang a little less than a 1/2", well, it's pretty close to spot on.

Oh, and wheel mount to wheel mount is not the same as flange to flange when ordering the rear axle. To get from wheel mount to wheel mount to flange to flange, measure how thick those rear disks are and subtract that. Clear as mud?


You might want this too, this is what I use to compare wheels once I have the measurements
Custom wheels, rim tire packages
 
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72blu You rock man! Thank you so much for this information, it is very good stuff.

I can see why the 6k is worth it though - that trans set-up sounds really, honestly, nice. I am thinking of running a beefed up 727 behind mine only because I am not sure I want to go through all the effort of fabricating a 4 speed to the car even though I really think it would be cool. How hard was yours and how much did you spend on the whole set up if you don't mind me asking? Do you think that A833 is a better option?
 
72bluNblu said:
I like the fast ratio, 16:1 manual steering. With 275's up front and +6.75* of caster it doesn't make for much fun if you're parallel parking, but once you're going 10mph or so it's awesome. That's the same ratio as the stock power steering, just without the boost. For power steering I would just convert to the Borgeson box Peter sells, it's 14:1 and is significantly smaller and lighter than the stock power steering box.

Radiator mounts? I have a Champion 26" radiator, it's made to fit an A-body. My car had a 22" radiator originally though so I just drilled a couple of holes and welded nuts onto the back of the radiator support, just like stock.

I do like US Cartool's stiffening parts, except for the subframe connectors. They look great and they're strong, but they're a pain in the butt to install compared to a tubular set. But if you have the Hotchkis one's I wouldn't worry about it, those are good. But the US Cartool torque boxes, front inner fender braces, and radiator support brace are nice. I installed pretty much everything US Cartool makes on my '71 GT, the USCT subframes are the only part I wouldn't do again. The radiator support brace probably isn't as strong as the full tubular brace I installed on my Duster, but it looks more stock than the big round tube I've got. Same for the inner fender/shock mount braces. The J bars I have on the Duster are probably stronger, but the US Cartool pieces aren't nearly as obvious or in the way. And they do a lot to add stiffness to the chassis.

For the rear axle, I think with 575 hp I'd just go straight to a Dana 60. I don't think I'd use the 8.25" with that kind of power. It might be ok for just a street driven car, but with any kind of track time I don't think I'd mess with it. The 8 3/4 would work, but if you don't have one already the cost won't be all that much less than a Dana 60 by the time you've built a solid 8 3/4 up. I just ordered a new 3rd member for my upcoming T56 swap, with a new housing, HD adjusters, 1350 yoke, Truetrac and 4.30 gears it was $1375 from Dr. Diff. Good price considering it's a new 3rd member. But I already have the B-body 8 3/4 installed in my car, axles, etc. If you didn't have an 8 3/4, and for a Swinger I'd want something close to the original A-body width, you'd either have to buy an A-body housing (pricey!), or find a 65-67 B body housing. Or have one shortened with a custom width. Rather than do all that I'd just have Dr. Diff built a new strange S60 and have it set up exactly how you want it for perches and overall width. Might cost a little more all said and done, but maybe not depending the axles and stuff for the 8 3/4.
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Re: the Dr.Diff Dana60. I just went that route because I killed my 7 1/4 and am building suspension and trans/rear before I start on the stroker. Expect to spend about $4200 plus labor if you have a damned home owners' association. Cass at Dr. Diff is very helpful. I skipped the 8 3/4 because I only want to buy the rear end once. It's only a couple hundred bucks more.

The thing I do like about the 8 3/4 is the ability to swap gearing in an afternoon.
 
Luckily we're pretty damn well connected in the Northern California area. We have a lot of friends in the business and people are always willing to take time to help, of course we do the same all the time too. I can't count the number of times in high school I had to strip an old car down for my dad trading out favors. So I really only need to pay for parts.

As for the Dana I am looking at Dr. Diff and unless I am missing something it should not be more than 2300 bucks for the complete rear end. Please, if I have missed something inform me so I am aware before I order haha.

What are you running Transmission wise?
 
Oh, welcome from Santa Rosa! :)

I had to get disk brakes, lines, shock plates, everything. When I get home tomorrow, I can look up all the stuff I ordered. Oh, I forgot, shipping about $300 total.

I went with 4.10 gearing since my commute is a whopping ten miles, and Sears Point (Sonoma raceway) is only 20 miles from home and 10 miles from work. When I get the barracuda in racing condition, I can cut out of work early on Wednesdays for the races. $25 to enter, and $10 for my woman. Now, that's a cheap date!

Trans is fresh 727 from 727specialist, if I remember right, name is Keith.
 
Great information - Do you know if he does any sort of kit for the 727 or do you have to have them custom built by him? I have a couple people here who are willing to do it if I provide all the parts but I haven't been able to just source a kit to handle up to 600HP - I will be running about 575ish give or take 10HP.

I am thinking about the 4.10 gearing as well since I am about 5 minutes from work and anything I need is in a 10 mile radius. Would you recommend it over the 4.30?
 
If I remember right, his website is 727specialist.com. One person you may want to talk about transmissions is younggunn2.0. He did a thread on building one about a year ago I think, and put it behind a 470.

I planned the 4.10 gearing for the future. Winding a 318 to 4 grand for a ten mile commute isn't a big deal to me, it's not like we drive these cars just to listen to the crappy little AM radio.

I am not too concerned about my 727 handling that much power because it's behind my 318 for now. I have two engines to build, a 318 in the shed to be bored and stroked to a 392 Wedge, and a 400 block for later after I get the experience of the small block. Since that will require a different trans, which will be a Gear Vendors OD 727, the 4.10 gearing will be a moot point. The big block build is years down the road.
 
Ottmundr said:
If I remember right, his website is 727specialist.com. One person you may want to talk about transmissions is younggunn2.0. He did a thread on building one about a year ago I think, and put it behind a 470.

I planned the 4.10 gearing for the future. Winding a 318 to 4 grand for a ten mile commute isn't a big deal to me, it's not like we drive these cars just to listen to the crappy little AM radio.

I am not too concerned about my 727 handling that much power because it's behind my 318 for now. I have two engines to build, a 318 in the shed to be bored and stroked to a 392 Wedge, and a 400 block for later after I get the experience of the small block. Since that will require a different trans, which will be a Gear Vendors OD 727, the 4.10 gearing will be a moot point. The big block build is years down the road.
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All great info , BUT, if ur wheel wells are the same as a 68 barracuda, (I don`t have a clue), u could get a 295 65 15 under it w/o major surgery. Will require rolling the inner lip, full 3/4" offset spring hanger kit (bolt on), and recontouring ur front wheel opening, which can be done to look stock. I did it to my fish. See my avatar pic / back when setting in the paint shop.
 
famous bob said:
All great info , BUT, if ur wheel wells are the same as a 68 barracuda, (I don`t have a clue), u could get a 295 65 15 under it w/o major surgery. Will require rolling the inner lip, full 3/4" offset spring hanger kit (bolt on), and recontouring ur front wheel opening, which can be done to look stock. I did it to my fish. See my avatar pic / back when setting in the paint shop.
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Except his wheel wells ARE NOT the same as a Barracuda. Swingers, Valiants, Scamps, etc have a full INCH less space in the wheel wells than Dusters, Demons, Dart Sports, and Barracuda's. Which I've even already mentioned in this very thread. The widest tire's you can get on the Swingers is a 275, and that's after a spring offset kit and usually a quarter lip roll. You can't get 295's on a Swinger without a mini-tub. Not only that, but the wheel arches on the rear of a Barracuda are much higher, so you can cheat some and hang the tires outside of the quarters a little if your ride height has some rake. The low wheel openings on the Swingers mean you can't get away with that unless you jack it up like a 4x4 in the back. And I don't even mean like 70's street freak style, you'd literally have to raise the back end of a swinger a good 6" or more to do that. Or cut the wheel arches like the factory Hemi darts.

74SwingerA said:
72blu You rock man! Thank you so much for this information, it is very good stuff.

I can see why the 6k is worth it though - that trans set-up sounds really, honestly, nice. I am thinking of running a beefed up 727 behind mine only because I am not sure I want to go through all the effort of fabricating a 4 speed to the car even though I really think it would be cool. How hard was yours and how much did you spend on the whole set up if you don't mind me asking? Do you think that A833 is a better option?
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The 833 is a good option, like anything it just depends on your plans for the car. If it's just an around town car that doesn't get driven a lot you can get away with 3.91's or 4.10's maybe. There's no way in hell you'll be able to spend any time on the freeway with those gears though, I think the 3.55's are pretty much the limit for any kind of freeway driving much more than 30 minutes or so.

The conversion to an 833 has a pretty wide range of costs. If you go to Brewers I think you'd end up with a quote somewhere around $3,500. They don't list their price anymore for their full conversion kit, but I recall it being close to that. But, all the parts are factory, so, you can find them all used too. And that can drop your price pretty substantially if your patient and get decent prices on used parts. I think my conversion initially was between $1,500-$2k when I did it. But I gathered the parts over a couple years, found an 833 for only $500 and rebuilt it myself, etc. So it just depends on how you do it. All new parts etc will probably be around that $3,500 mark, all used parts could be half that pretty easily if you can find everything for a good price.
 
72bluNblu said:
Except his wheel wells ARE NOT the same as a Barracuda. Swingers, Valiants, Scamps, etc have a full INCH less space in the wheel wells than Dusters, Demons, Dart Sports, and Barracuda's. Which I've even already mentioned in this very thread. The widest tire's you can get on the Swingers is a 275, and that's after a spring offset kit and usually a quarter lip roll. You can't get 295's on a Swinger without a mini-tub. Not only that, but the wheel arches on the rear of a Barracuda are much higher, so you can cheat some and hang the tires outside of the quarters a little if your ride height has some rake. The low wheel openings on the Swingers mean you can't get away with that unless you jack it up like a 4x4 in the back. And I don't even mean like 70's street freak style, you'd literally have to raise the back end of a swinger a good 6" or more to do that. Or cut the wheel arches like the factory Hemi darts.



The 833 is a good option, like anything it just depends on your plans for the car. If it's just an around town car that doesn't get driven a lot you can get away with 3.91's or 4.10's maybe. There's no way in hell you'll be able to spend any time on the freeway with those gears though, I think the 3.55's are pretty much the limit for any kind of freeway driving much more than 30 minutes or so.

The conversion to an 833 has a pretty wide range of costs. If you go to Brewers I think you'd end up with a quote somewhere around $3,500. They don't list their price anymore for their full conversion kit, but I recall it being close to that. But, all the parts are factory, so, you can find them all used too. And that can drop your price pretty substantially if your patient and get decent prices on used parts. I think my conversion initially was between $1,500-$2k when I did it. But I gathered the parts over a couple years, found an 833 for only $500 and rebuilt it myself, etc. So it just depends on how you do it. All new parts etc will probably be around that $3,500 mark, all used parts could be half that pretty easily if you can find everything for a good price.
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Good info on the wheel wells; do u know how wide a tire will work on the 68 fastback w/ the inner wheel wells just moved to the frame ? Like I said, I have 295 65`s under it now. Really not interested in moving the springs inboard. Looks like it would give about 2" more tire. ????
 
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