Wheel to spring clearance

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These Cragars are the unilug type, so I'm hoping the bolt pattern will fit a 5 on 4. Had them on a RR, 5 on 4.5, and they worked great! If not I guess I'll be sending the axles off to MOSER for re drilling to 5 on 4.5.
 
Hey Coyote Jack. I have a dart sport and want to get wheel close to outer rear fenderwell. So 15x8 & 4" backspace seems like the route go. Is your car rear wheel cloe to fenderwell?

I wanted the same thing with my Dart because I thought it looked goofy having the tires tucked back in the wheel well.
Got 245/40R18 on it with 1 inch to spare inside and out, and trimmed the fender lip just for a little extra for corners.
The wheels and tires both are 9.5 inches with 5.5 backspace on the wheelsand I had 5.5 from the wheel mounting surface to the leaf spring edge, so I moved the springs in 1/2 on each side. (no kit, just some mods to brackets, perches and mounting points.)
It filled the wheel well up nicely, and got the rim and tire out there closer to the body lines which was the whole point.
Darts and Dart Sports are a little different apparently, but just so you know I think it was worth every minute of the labor and time.
 
Hey Coyote Jack. I have a dart sport and want to get wheel close to outer rear fenderwell. So 15x8 & 4" backspace seems like the route go. Is your car rear wheel cloe to fenderwell?

Dart Sport's are completely different than Dart's. The Sport body has an extra 1" of width in the stock wheel houses, same as the Demon/Duster and Barracuda's.

As far as "getting the wheel close to the outer fenderwell", if you get it closer than a 1/2" your tires will rub. You don't mention what rear axle you have or what bolt pattern, both of which are very important in determining backspacing because all the different A-body rear axles are actually different widths (7.25 vs 8.25 vs 8 3/4, sbp vs bbp). The rear axle and bolt pattern are as important as the size of the tire you plan to run in figuring backspace.
 
Here is the setup I had.

72 Demon
8 3/4 rear
large bolt pattern
Yukon axels (stock length)
green bearings
15x8 American Racing Outlaw 1
4 inch back spacing
M/T Sportsman ST 275-60-15 (At first I had M/T Sportsman Pro 255-60-15's, they fit better)
My tires did not rub on the outside or inside. However they did rub on the front wheel well area if I had 4 in the car and was getting on it.

Hope this helps.

Jack
 
Here is the setup I had.

72 Demon
8 3/4 rear
large bolt pattern
Yukon axels (stock length)
green bearings
15x8 American Racing Outlaw 1
4 inch back spacing
M/T Sportsman ST 275-60-15 (At first I had M/T Sportsman Pro 255-60-15's, they fit better)
My tires did not rub on the outside or inside. However they did rub on the front wheel well area if I had 4 in the car and was getting on it.

Hope this helps.

Jack

Sure, but what rear springs were you running?

The picture in your photo garage says it all- the section width of those tires is even with the outside lip of the quarters. The only reason they don't rub is the massive rear ride height. If there wasn't a 4"+ gap between the top of the tire and the quarters, they'd rub. The stock quarter lip is 1" wide, those tires will never clear that if they ever ended up at the same altitude as the quarter lip.

With an A-body 8 3/4, BBP axles, stock springs and 275's on a 15x8 you want 4.5" of backspace. The tires will fit inside the quarters, and you can run at stock ride height or even a little lower. Otherwise you have to run it 70's street freak style with the rear end of the car jacked way up in the air. Which is fine if that's what you want, but 275's will actually fit inside the stock wheel houses with the proper backspace

i16816-jpg.jpg
 
Dart Sport's are completely different than Dart's. The Sport body has an extra 1" of width in the stock wheel houses, same as the Demon/Duster and Barracuda's.

As far as "getting the wheel close to the outer fenderwell", if you get it closer than a 1/2" your tires will rub. You don't mention what rear axle you have or what bolt pattern, both of which are very important in determining backspacing because all the different A-body rear axles are actually different widths (7.25 vs 8.25 vs 8 3/4, sbp vs bbp). The rear axle and bolt pattern are as important as the size of the tire you plan to run in figuring backspace.
My rear end is a 8.25. My bolt pattern is the modern 4 1/2. Rear leafs are mopar performance muscle car leafs. Willing to trim inside fender lip to accomodate tires. Oh tire size is 275/60/15's. May consider 295/50/15. But not sure just yet! Just want to fill rear wheel well nice and good.:D
 
Found some 295/50 15 tires on 15 by 10 Centerlines. Sure would like to buy them, but now I'm thinking they may not fit on back of my 70 Dart Custom. Any ideas?
 
The only way they will fit is moving the springs into the frame and have lots of backspacing!!! I've never been able to use a wheel wider than 7 inches in the back of my 70 Dart Custom and still have enough room not to cut the sidewall when the car is loaded to the side in a tight turn. I tried 8s and cut up the inside sidewall on the clamps on the springs.
 
...and that was with the MP spring relocation kit with offset shackles - which I would recommend if you are replacing or taking out the rear housing (you have to cut off the old perches and put in new ones).
 
Sure, but what rear springs were you running?

The picture in your photo garage says it all- the section width of those tires is even with the outside lip of the quarters. The only reason they don't rub is the massive rear ride height. If there wasn't a 4"+ gap between the top of the tire and the quarters, they'd rub. The stock quarter lip is 1" wide, those tires will never clear that if they ever ended up at the same altitude as the quarter lip.

With an A-body 8 3/4, BBP axles, stock springs and 275's on a 15x8 you want 4.5" of backspace. The tires will fit inside the quarters, and you can run at stock ride height or even a little lower. Otherwise you have to run it 70's street freak style with the rear end of the car jacked way up in the air. Which is fine if that's what you want, but 275's will actually fit inside the stock wheel houses with the proper backspace

View attachment 1715276843

That's an optical illusion in the photo. The tires did fit inside the lip. It took 600 lbs in the trunk to find out for sure but they did fit by 1/2 an inch. Those are SS springs by the way.

Jack
 
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