Demon Rear Wheels

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Bethany Demon

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I'm new to the club and I'm sure this question has been asked many times in the past. My question is what width wheels are the widest that will fit in a typical A Body (In my case a 71 Demon)? Basically I'd like to run 15 x 8 wheels but I need to know if they will clear and if so what backspacing should they be. Thanks in advance.
 
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just learn how to measure for wheels on YOUR car. they all vary greatly from the factory and asking what someone else is running is just setting yourself up for problems imo
 
Also remember to factor in the section width of the tire. Its generally the widest point of a tire. I measured based on tread width..... Tire fits great, right up to the point that I hit a big bump.
 
How much work/money do you have to spend?
I put N50s on mine, back in the 70s.........but I had to lift the back up a bit.......
275/60-15s on 8.5s fit my stock tubs with 4.5 bs, (I mighta had the springs moved by that time, not sure),
I put 325/50-15s on 10s,into the factory 68 Barracuda tubs .......but that wasn't a bolt-on.......lol, I narrowed the rear and moved the springs . This is the best way, cuz you can use whatever wheel you want/like. I highly recommend you not try 325s; they were an extremely tight fit, with a lot of massaging, in my lowered Barracuda, and I cannot fly around the turns with them on,but........... Dang do they look good in there.
But I take the 325s off and install 295s, and then it's business as usual.These are also on 10s with 4.5bs. I like the look of those 70s ETII type wheels, and have quite a collection already.295s want a wider wheel, but I have found that at 24psi, I can get good treadlife out of them. But it does roll over the sidewalls on fast turns, giving me some rear steer, which I have gotten used to and now actually wait for it and use it,lol.

So what you do is take the rear end right out,springs and all. Then put your wheels and tires of choice in there, and drop the body down to your desired ride height. Then center the stuff up in there, and drop the body another 1.5 inches, for suspension travel,and the readjust the wheels as may be necessary. Next, you measure between the wheel mounting surfaces, and write that down. then you subtract 1/2 inch in case you screwed up. And finally you order your narrowed rear end to that spec.but with loose perches.
When it come in, you move the springs and rough it all in, again centering everything.Then if the wheels rub...it will be on the inboard side, and you just install some spacers. But if you had screwed up to the outside, you would have had to roll the lips.
And finally, you set the pinion angle and weld the perches in.
That's how I did it, and thank goodness I made the rear end that 1/2 inch narrow.
 
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AJ/FormS said:
How much work/money do you have to spend?
I put N50s on mine, back in the 70s.........but I had to lift the back up a bit.......
275/60-15s on 8.5s fit my stock tubs with 4.5 bs, (I mighta had the springs moved by that time, not sure),
I put 325/50-15s on 10s,into the factory 68 Barracuda tubs .......but that wasn't a bolt-on.......lol, I narrowed the rear and moved the springs . This is the best way, cuz you can use whatever wheel you want/like. I highly recommend you not try 325s; they were an extremely tight fit, with a lot of massaging, in my lowered Barracuda, and I cannot fly around the turns with them on,but........... Dang do they look good in there.
But I take the 325s off and install 295s, and then it's business as usual.These are also on 10s with 4.5bs. I like the look of those 70s ETII type wheels, and have quite a collection already.295s want a wider wheel, but I have found that at 24psi, I can get good treadlife out of them. But it does roll over the sidewalls on fast turns, giving me some rear steer, which I have gotten used to and now actually wait for it and use it,lol.

So what you do is take the rear end right out,springs and all. Then put your wheels and tires of choice in there, and drop the body down to your desired ride height. Then center the stuff up in there, and drop the body another 1.5 inches, for suspension travel,and the readjust the wheels as may be necessary. Next, you measure between the wheel mounting surfaces, and write that down. then you subtract 1/2 inch in case you screwed up. And finally you order your narrowed rear end to that spec.but with loose perches.
When it come in, you move the springs and rough it all in, again centering everything.Then if the wheels rub...it will be on the inboard side, and you just install some spacers. But if you had screwed up to the outside, you would have had to roll the lips.
And finally, you set the pinion angle and weld the perches in.
That's how I did it, and thank goodness I made the rear end that 1/2 inch narrow.
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this sounds like a good plan, but I`d roll the lips anyway, use all the space u can create , is my opinion.
 
I ran 255/60 X 15 on 8 '' rims on the rear of my Dart Sport for years. I heard some people go as high as 275s. This is what they replaced the Demon with after the religious controversy in 71 & 72. That is why you won't find a 73 Demon, the name changed but not the body.
 
15x8's will fit, 275's will fit most Demons/Dusters/Dart Sports without any modifications to the quarter lips. Body tolerances and ride height make a difference so measure your car.

Backspace depends on which axle you have and what bolt pattern/brakes you're running, if you let us know that we can give you a decent estimate for backspace.
 
Look up how to measure your backspace and do that. On my 74 Duster, you don't really want to go wider than 245-60-15 on a 8 inch rim. You might be able to squeeze a 255 but you might have to do some slight modification.
 
TF360 said:
Look up how to measure your backspace and do that. On my 74 Duster, you don't really want to go wider than 245-60-15 on a 8 inch rim. You might be able to squeeze a 255 but you might have to do some slight modification.
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So what are your measurements? I would love to see your spring to quarter lip measurements, or wheel mount to spring and wheel mount to quarter measurement, or whatever you've got. Tire to quarter and tire to spring would work too. Every Duster/Demon/Dart Sport I've seen has ~12" from spring to quarter lip with the springs in the stock location and a stock quarter lip. And that's more than enough to run a 275/60/15 on a 15x8 with the right backspace, even on a lowered car, because a 275/60/15 has an 11" section width. So, properly centered, a 1/2" of clearance on either side. Which is tight, but enough not to rub.

I've seen you post this multiple times now, and disagree with my assessment that 275's will fit a stock, unmodified Demon/Duster/Dart Sport even though I've run 275's on my own car without modification. And there are at least a dozen other active members on this board with stock Dusters/Demons/Dart Sports running 275's with unmodified quarters and the stock spring locations.

I'm not saying your car can, because there are definitely body tolerance ranges on these cars and there are definitely cars that can run wider tires than others. But if your Duster can't go more than a 245/60/15 in the back with the proper backspacing, it would literally be the only one I've heard that was like that.
 
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Bigger is not always better. Look at the Centerlines for sale thread, and read what the guy says. 1/4 inch space is not enough. I guess it works for you, but on many cars It wont. My opinion is that it is too close
 
TF360 said:
Bigger is not always better. Look at the Centerlines for sale thread, and read what the guy says. 1/4 inch space is not enough. I guess it works for you, but on many cars It wont. My opinion is that it is too close
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And? The seller in that thread has 15x8's with a 5" backspace, and found that only gave him a 1/4" to the springs. That means, with a 1/4" spacer, those rims and tires would fit perfectly. Heck even with an 1/8" spacer they'd probably fit. I sent him a PM to let him know exactly that, and will be happy to help him figure out how to get those wheels to fit his car. Because I bet they will.

That's why I always say "with proper backspacing". You can make any size tire not fit correctly if you're using rims that don't have the proper backspace.

So, what are your Duster's measurements? How much clearance do those 245's have to the springs and the quarters?
 
72 -I have some space on the inside only about 1 1/2 inches. No space at all on the outside. If I pulled the inward one more size that's about all that would fit properly. My opinion.
 
TF360 said:
72 -I have some space on the inside only about 1 1/2 inches. No space at all on the outside. If I pulled the inward one more size that's about all that would fit properly. My opinion.
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You have an inch and a half to the springs? And your tires don’t rub on the quarter. Good grief man.

AJ did the math already, you could totally put 275’s on your car if you had the right backspace on those wheels. He’s figuring 3/8” to the springs, which is tight, but he also runs his car like that so you’d better believe it works. Because if he can’t make his tires rub with 3/8” of clearance they won’t rub. :D And if they don’t rub, they fit.

So, I get why you run 245’s, you’d have to buy new wheels because your current wheels have the wrong backspace to go any wider. And it’s true, 255’s are definitely easier to fit than 275’s because you have more leeway on the backspacing. With 275’s you’ve got to be pretty much dead on with the backspace.

But do me a favor and stop telling people you can’t run 275’s on a stock Duster. Because you could run them on your car if you wanted to buy wheels with the right backspace. You choose not to, and that’s totally fine, no one says you have to run 275’s. But you could if you wanted to. So stop telling other people it can’t be done because you don’t want to bother trying.
 
I won't agree with you. Telling people to leave 1/4 inch space is not enough in my opinion. You can get them on there, but that does not make it right. Some tires are a hair wider than others, and that's cutting it too close.I bet you guys have some rubbing going on. 255 is a better choice. I think you should stop telling people to run 275's because the majority of people don't want to run a spacer or buy a custom wheel for more bucks. I'm not upset with you. You are knowledgeable for sure. But I have my opinion, and you have yours.
 
TF360 said:
I won't agree with you. Telling people to leave 1/4 inch space is not enough in my opinion. You can get them on there, but that does not make it right. Some tires are a hair wider than others, and that's cutting it too close.I bet you guys have some rubbing going on. 255 is a better choice. I think you should stop telling people to run 275's because the majority of people don't want to run a spacer or buy a custom wheel for more bucks. I'm not upset with you. You are knowledgeable for sure. But I have my opinion, and you have yours.
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I've never told anyone to run a 1/4" of clearance, so I'd really appreciate you not lying about what I've said. Not even the math from your car works out that way. AJ did it above. You get 3/8", and he runs that, and he says it works (as do a lot of people).

As for what the "majority" of people want, why don't you let them decide? The 275's will fit with proper backspace. Yes, that might take a spacer or a custom rim to achieve on some cars. But most of them fit with 15x8's on with 4.5" of backspace, and that's an off the shelf rim. If someone doesn't want that, they don't have to do it and they can run narrower tires. Just like you do. The facts don't change because you decided not to buy new wheels or accept the possibility of running a small spacer (which is completely safe and approved by many racing organizations).

So here's a quick list of a dozen other members currently running 275/60/15's on unmodified sport body cars. I only used examples for cars that the owners said were stock, and had posted a picture for, and I left my car with 275's on it out just in case you think I'm biased. There are tons more folks that have said they've done it without posting pictures. And I'm sure there's even more that I haven't found, but I wanted to limit this to 15 minutes of my time. So, either all of these people are lying about their cars, or you're incorrect. That doesn't mean you have to run 275's, do whatever you want. But it can be done successfully, without rubbing, because they will fit with the proper backspace. And now I can just reply with this post anytime you say they won't fit, so folks have evidence to make their decision.

They fit on DakotaDuster's unmodified '74 Post your wheel and tire combos.
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And 1969cuda340 has them on an unmodified '74 Post your wheel and tire combos.
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And petnic01 has them on a '73 Duster (not any different than a '74 for tire clearance) 73 duster 275/60/15????
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And Sweet416 has them on a Dart Sport (not sure what year, doesn't matter, all the same) 275's on a dart sport
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Mopowers runs them "no problemo"Father-Son 1974 Duster Project
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OL DODGE did it on a '73 Duster 340 73 duster 275/60/15????
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Oldmanmopar runs 275's on his Duster 275/60/15 tires on stock Duster
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Fisher runs 275's on his Duster 275/60/15 tires on stock Duster
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Sireland67 runs 275's "no issues" 275/60/15 tires on stock Duster
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71DodgeDemon340 runs 275's on his '71 Demon front tire size advice
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67autocross with a '70 Duster and 275's Post your wheel and tire combos.
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Mguner's Dart Sport with 275's Wheel/tire combo for '73 Dodge Dart sport
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TF360
This is not directed specifically at you so don't take umbrage

I run 295s INSIDE my 68 Barracuda wheel wells, with the body dropped down over them, a bit, cuz I like it low. And I NEVER think about them Cuz rubbing is a non-issue.
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I fit 325s in that same set-up, and in a straight line, it's a non-issue. And driving nice, turns aren't either. I just can't charge as hard as I like to. I have set it up to rub on the inboard side, and smoothed the part where it consistently rubs, so it doesn't damage the sidewall. It's about a quarter inch there, and close to a half on the outboard. My springs are running nearly flat,ie; almost no camber, and I run the poly stuff.So my body sways very little back there. But I run 24psi in the 325's cuz they are on 10s, which is really not enough width.If I ran more, I would ruin those expensive DRs pretty quick. And even with the sidewall roll-over, they don't get into the relocated springs. The 325s are not totally inside the wells; the outboard sidewall is flush with the body line. So I had to fold the lip up and a little tighter to the body. So now I have about 1.5 inches (from memory) of allowable suspension jounce. Yes,I run spacers; that's what long studs are for. IIRC ( It's been a very long time since I checked), I run .25 on one side, and .125 on the other; so I guess you could say I goofed when I welded the perches in, because I originally planned to run .25 on each side,lol.
This is what HotRodding is all about; making stuff work.

A hot teener or even a warm360, has traction issues. Why bother building a 350/400 hp streeter just to shoe it with 245s or maybe 255s. IMO,That's insanity. So you got $4000 or maybe $6000 in your engine, and the guy next door with his punk tuner car embarrasses you every chance he gets. What? You say you ignore him? Need I say more?
The bottom line is; a stout 360, without traction aides, spins even 325s to 60,70 and more, mph. So why would someone put skinny rollers back there? Even my winter engine spun old hard 275/50-15s a good ways with a 10.97 starter gear, and it was a factory original 1973 teener with just; a re-ring, a TQ, and the exhaust system of my summer 367. That was actually a very fun winter combo.

Okay, I know a Barracuda is not a Duster/Demon......I believe it has about a half to one inch more room before you start massaging. But from 295 on 10s, to 275 on 8/8.5s, is 2 full inches.
Now, in case we forgot, here is the OPs origial query
Bethany Demon said:
I'm new to the club and I'm sure this question has been asked many times in the past. My question is what width wheels are the widest that will fit in a typical A Body (In my case a 71 Demon)? Basically I'd like to run 15 x 8 wheels but I need to know if they will clear and if so what backspacing should they be. Thanks in advance.
Click to expand...

So I guess my answer to the first question,would be; With relocated SS springs and long shocks, you could maybe get 325 on 10s, back there. But you might be ticketed for the part that sticks out past the bodyline. So to avoid the tickets, make it 295s.
And as to the second question; For a streeter, about the widest you can put on an 8 is a 275/60, and still run reasonable pressure of about 28psi. If you put a 275/50 on there, You will have to drop the pressure pretty close to 24. And 24 handles like crap, until you are spinning BOTH tires in second gear. But by then you have probably spun out and mounted the center median, and are facing backwards, with both the clutch pedal and the brake pedal , firmly planted on the floor. Try not to blame it on the tires........
The 275/50 wants a 9" rim to run proper pressure, but those are somewhat hard to find. Second best is an 8.5 . But....IMO 275/50s are too low anyway at 25.8, compared to 275/60s at 28. These tall-boys look better,and are about as tall as you dare put back there, so tuck 'em in.They handle better on 8.5s too. And the 28s will offer better traction than the shorter tires.
If you can't spin 'em, you need more TC, or more gear.....not necessarily more motor.
72 bluNblu..... knows the backspaces
 
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