Have you worked out a drive shaft deal yet that doesn't cost a grand?
I am thinking about maybe a junkyard slide shaft from a 4wd truck.
BTW what part of GA are you in? I'm in Lawrenceville.
318/8 Speed Swap
- Thread starter wish4hemi
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Have you worked out a drive shaft deal yet that doesn't cost a grand?
I am thinking about maybe a junkyard slide shaft from a 4wd truck.
BTW what part of GA are you in? I'm in Lawrenceville.
iḿ waiting for this , if it is made the 426 stroker goes back in the Dart , might get better than 8 mpg , if it gets 15mpg i can live with that at $8.00 a gallon gets expensive driving 120 miles a day . My 550 hp range rover gets decent mpg because of the 8 speed
roadrunninMark
Well-Known Member
Hello Mgo, I am in Fayetteville. I plan on using the 2 piece driveshaft from a ram but I think it was from a rear wheel drive. The second part of the shaft has the slip joint. The front section has the output mount for the trans so the plan is to remove that and put on where it joined the mid mount. It is a universal joint there too so it should just bolt in its place. The length hasn’t been worked out yet but it is in the ballpark but the shop I am working with on the car says they should be able to fix the length. Were you still interested in the flex plate I have for sale (moparts mail)?
Nat, it is in progress finally. I posted a link earlier in the post about someone who made his own adapter for a big lock but I also think JVX Racing in Tenn. has a big block adapter. They are making the flex plate kit to go right in. I am using that instead of modifying the Quicktime plate, less chance of problems.
Nat, it is in progress finally. I posted a link earlier in the post about someone who made his own adapter for a big lock but I also think JVX Racing in Tenn. has a big block adapter. They are making the flex plate kit to go right in. I am using that instead of modifying the Quicktime plate, less chance of problems.
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About what year was the truck? Was it club cab and long bed, or do shorter versions have the same type shaft?
I found the JVX plate as well and will run it to keep it simple. He has one for the magnum engines that works with the crank sensor.
BTW there is an company on ebay that does made in USA driveshafts with the 2 piece slide up to 72" long for less than $300.
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72Duster440
Well-Known Member
Denny's Driveshafts, High Angle Driveline, Tom Woods, and any local shop should be able to build you a driveshaft for that application. You just need a slip joint in the driveshaft.
roadrunninMark
Well-Known Member
I don't recall what it came out of as I bought it from Craigslist. I do have part numbers off of it...
P52123616AA its at the shop with the car but the part with the slip joint, the length is close for a barracuda, challenger would be a little longer of course. I think it will need to be cut down.
I don't know about the ebay shafts, might be something to look into if needed. I got the ram shaft fairly cheap plus it has the correct mount for the back of the trans.
OK, I thought you wanted the Quicktime plate for the engine run stand setup.
P52123616AA its at the shop with the car but the part with the slip joint, the length is close for a barracuda, challenger would be a little longer of course. I think it will need to be cut down.
I don't know about the ebay shafts, might be something to look into if needed. I got the ram shaft fairly cheap plus it has the correct mount for the back of the trans.
OK, I thought you wanted the Quicktime plate for the engine run stand setup.
roadrunninMark
Well-Known Member
I've also been playing around with the shifter. The easiest would be to just mount the new shifter in place of the old slap stick. The sizes are close (I mounted a old style pistol grip to the stalk, not done yet). The stalk needs a sleeve to get it to the proper diameter but I think it will work. I have an idea of using the ram dial shifter and connect the shaft inside the dial to the original slapstick, so I can keep the look if the original.
Great progress! Can I ask how much "slip" is in this boot? Can you collapse this by a few inches? Or is it rigid and just for harmonics?
roadrunninMark
Well-Known Member
Hi Johnny, I never tried moving it in or out. It is at the shop with the car so I cannot try it. Maybe the next time I go down I will see how much movement there is. It isn't just for harmonics as the ram truck has a full floating rear axle like our cars and they have quite a bit of travel in the suspensions.
I would assume it has quite a bit of slip, but I would be very curious to know! I was surprised to find out the cars really don't have any, but they have that whole IRS cradle which as you are alluding to, doesn't move much if any.
roadrunninMark
Well-Known Member
Reviving this old thread.... work has finally begun getting the 8 speed in. I changed direction on the flywheel from the QuickTime -947 to a kit from JVX Racing in Tenn. He has a full installation kit to make the easy (he also sells the kit and adapter for a big block). Tunnel was cut and raised some. A custom cross member was made and the 8 speed mount used. Here are some pics:
that is major surgery . Raised some ?? How much was it raised looks substantial from the pics . Can´t wait for some road test results
wow I was shocked to see JVX does this for small block also. Really like the idea of this swap, I know other transmission could be used. This seems like the biggest upgrade I could do for my Dart with a built 360 being very happy in front of it. Seen many Dakotas and Magnum cars are loving the swaps.
DionR
Well-Known Member
Personal opinion, but I think the 8HP70 is a phenomenal transmission. Enough so that even though I have a new T56 in my garage for my Duster, I still sometimes wonder if the 8A wouldn't be the better direction.
But there is a caveat. If your motor isn't happy cruising under load at less than 2000 RPM, I wonder if it is the best idea. With a 26" tire and a 2.71 rear gear, 65 mph is about 1550 rpm and 75 mph is 1780 rpm, almost matching a new Challenger with the "performance" 3.06 rear gear. You could run a 3.55 gear instead and push the highway rpm's up to and above 2000 rpm in 8th but remember it has a 4.69 first gear. That gives you a 16.65 overall 1st gear ratio which would be like running a 727 with a 6.56 rear gear on the street.
Even with the 2.71 rear gear it is about the same as a 727 with a 5.00 gear, so still pretty deep.
You could run the 2.71 rear gear and only use 8th gear at 85 and above though. The A9 in my wife's 200 probably has less than a 1000 miles on 9th gear because it is too tall, so the OEM have done that. Or you could run a 3.55 rear gear and start in 2nd, that would like a 727 with a 4.37.
Plenty of options, just pointing out something to think about.
But there is a caveat. If your motor isn't happy cruising under load at less than 2000 RPM, I wonder if it is the best idea. With a 26" tire and a 2.71 rear gear, 65 mph is about 1550 rpm and 75 mph is 1780 rpm, almost matching a new Challenger with the "performance" 3.06 rear gear. You could run a 3.55 gear instead and push the highway rpm's up to and above 2000 rpm in 8th but remember it has a 4.69 first gear. That gives you a 16.65 overall 1st gear ratio which would be like running a 727 with a 6.56 rear gear on the street.
Even with the 2.71 rear gear it is about the same as a 727 with a 5.00 gear, so still pretty deep.
You could run the 2.71 rear gear and only use 8th gear at 85 and above though. The A9 in my wife's 200 probably has less than a 1000 miles on 9th gear because it is too tall, so the OEM have done that. Or you could run a 3.55 rear gear and start in 2nd, that would like a 727 with a 4.37.
Plenty of options, just pointing out something to think about.
man , i watched that video on the 5.7 and 8spd trans in the ramcharger , wow clean setup , makes me think what a great smogger swap . here in california every two years 1976 and newer must pass smog emissions every two years for life as i said . and this would be ideal for my shop truck commuter . out with that 318 injected pup and in with a newer hemi . hell i might even do the bodywork n paint it , i'm modifing up a set of old school vintage 200s's for it now .
Yeah I wonder if the 2.94 would not be enough 2000 rpm would be perfect at 75 3000 is driving me nuts. No way would I go 3.55 on a 727. I would slit my wrist after an hour at 3400 rpm 75 mph and wife yelling at me LMAO.
72Duster440
Well-Known Member
Ha, try it with 3.91s, I'm pushing 3500rpm going 65-70. It's getting kinda old, I plan to go to a 28" tire and some taller gears this winter to get below 3k at 70.
DionR
Well-Known Member
I'm running right around 2K @ 65 mph right now with a 25.6" tire, 3.21 gears and an A833OD. My expectation when I swap to the 5.7/T56 is 3.55 gears with a similar sized tire and 1500 rpm @ 65 mph, duplicating the rpm's my old '15 R/T ran.
My only point with my previous post was that the A8 could potentially introduce some new problems. If you put it behind a rowdy motor and expect it to cruise at 1500 rpm, your motor might not be happy at that rpm. And if you gear it so the highway rpm's better match your motor you can end up with 1st (and maybe 2nd?) gear being completely unusable. Or maybe you end up with a 7 speed trans because 8th is only useful on certain highways, or the Autobahn.
The 8A spreads the usable rpm's so far that the motor can start to be an issue, in my opinion. Just seems like EFI becomes more important so the motor runs smooth on both ends of the torque curve, or maybe a mild motor is better fit. Personally, it's one of the reasons I like the G3, it makes good power as a 5.7 and more than enough as a 6.4, but both are still efficient at 1500 rpm.
Not to say that there aren't wizards out there that could build a 500 hp 408 with a carb that can run smoothly under load at those lower rpm's. Just that it seems like the big HP usually came at the expense of low rpm drivability which seems like it could cause problems if you are asking the motor to spend a fair amount of time in those lower rpm's.
Just something to think about.
72Duster440
Well-Known Member
I completely agree with you. I looked into an 8 speed swap behind my big block last year. I had all the parts picked out and prices added up. It was a bit more budget than I wanted to use for a trans swap, but my motor doesn't like staying below ~2300 with a load for very long, so it would have involved some engine changes too. That was the deciding factor for me.
Mine is happyish at 1500 and 1600 golden 2000 but I think your right I would have to possibly go to 3.23 but was going to look at tremec calculator and ratios see what the that might be like on a 2.94. The 727 I hate great drag transmission but that's about it just chugs gas current configuration and still needs a 3.55 or at least 3.23. I either do something big like this or 6 speed as an hour drive I may have to stop and get fuel. Also the 727 is tired don't see it as well spent money.
72Duster440
Well-Known Member
The fuel aspect sucks, Mines the same way. I just switched to an 833 from my 727. Super fun to drive, but being heavy on the throttle my last tank was ~5mpg.
DionR
Well-Known Member
Just me personally, I think the a 2.71 rear gear is about the sweet spot for the 8HP70. This gives an overall first gear of 12.71:1. A 727 would need a 5:1 rear gear to match it. A regular 904 would need a 5.19 gear and a deep first 904 would need a 4.64 gear. Just for a comparison.
With a 25.8" tire this would put the motor at about 1550 rpm @ 65 and just over 2K @ 85. That's maybe a little low for the rpm at 65, but 7th puts it at about 1925 rpm. I could see 8th being only somewhat useful depending on the roads in the area.
I wouldn't go any taller than that on the tire though. Anything taller is only going to lug the motor even more.
I could see an 8HP70 with a 2.71 rear gear being a decent solution for you. It would accelerate harder than your current set by a lot, and while you might have to forgo 8th gear until you are on the major interstates, 7th would work great until then.
Hmm...interesting. I was just looking at what what the setup I spec'ed above would be like to drive around on the street. If I stick to the 2000 rpm minimum, 30 mph is 3rd gear, and 45 mph is 5th. Wouldn't even get into 1:1 (6th gear) until 55-60. I've only driven an 8A equipped Challenger a couple of times and never paid attention to what gear it was in, but I would bet it does something similar. Difference is, the G3 can be run at 1400 rpm so 30 mph in 5th works fine.
I wouldn't be surprised if 1600 at 30 mph is fine even if the motor is only "ok" at 1600 rpm on the freeway. That would put you in 4th and 1770 rpm @ 30 mph. So many variables, but I would bet it would work fine.
EDIT - I had the wrong speed for the 2k rpm in the combination at the top.
With a 25.8" tire this would put the motor at about 1550 rpm @ 65 and just over 2K @ 85. That's maybe a little low for the rpm at 65, but 7th puts it at about 1925 rpm. I could see 8th being only somewhat useful depending on the roads in the area.
I wouldn't go any taller than that on the tire though. Anything taller is only going to lug the motor even more.
I could see an 8HP70 with a 2.71 rear gear being a decent solution for you. It would accelerate harder than your current set by a lot, and while you might have to forgo 8th gear until you are on the major interstates, 7th would work great until then.
Hmm...interesting. I was just looking at what what the setup I spec'ed above would be like to drive around on the street. If I stick to the 2000 rpm minimum, 30 mph is 3rd gear, and 45 mph is 5th. Wouldn't even get into 1:1 (6th gear) until 55-60. I've only driven an 8A equipped Challenger a couple of times and never paid attention to what gear it was in, but I would bet it does something similar. Difference is, the G3 can be run at 1400 rpm so 30 mph in 5th works fine.
I wouldn't be surprised if 1600 at 30 mph is fine even if the motor is only "ok" at 1600 rpm on the freeway. That would put you in 4th and 1770 rpm @ 30 mph. So many variables, but I would bet it would work fine.
EDIT - I had the wrong speed for the 2k rpm in the combination at the top.
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DionR
Well-Known Member
Something to be aware of is, the tallest ratio I can find for an 8.75" is 3.23:1 in new ring and gear sets. Kind of makes the 2.71 gear I would want a bit of a question.
I found a 2.76:1 for an 8.25", but even the 8.8 and 9.25 are limited to a 3.08 or 3.21 or above.
Used gears are an option, just saying that buying new setup might pose a problem.
I found a 2.76:1 for an 8.25", but even the 8.8 and 9.25 are limited to a 3.08 or 3.21 or above.
Used gears are an option, just saying that buying new setup might pose a problem.
roadrunninMark
Well-Known Member
My car has a 2.76 gear in it now, 8 3/4. You would have to find used for that gear. I need a sure grip still. From what I understand the C bodies had 2.76 sure grips. Also thinking since my car is probably 900 lbs or so lighter than a new challenger, the 2.76 might be just right. I could step up to a 2.94 too, if it "lugs" too much. I am estimating my engine putting out around 400hp, so I am in the window of a stock 5.7 hemi. I haven't selected tires yet though I do like the "steelies" with dog dish caps. I was thinking of 275/60-15 or 295/50-15 if I stay with those rims. 275/60 is 28"D and the 295/50 is 26.6"D.
I don't know how much it was raised but I told the shop I am using a shaker hood so the engine has to be in the stock location. They assured me it is. I think they took the conservative route and just cut a lot to be sure. I wasn't planning on this as I wanted to use the stock console but that isn't going to happen now. I am fitting in the new challenger console, which solves the shifter issue I was going to have.
I don't know how much it was raised but I told the shop I am using a shaker hood so the engine has to be in the stock location. They assured me it is. I think they took the conservative route and just cut a lot to be sure. I wasn't planning on this as I wanted to use the stock console but that isn't going to happen now. I am fitting in the new challenger console, which solves the shifter issue I was going to have.
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