I know there are other threads but what the heck. I have a 71 dart and I wanna know how wide of rim and tire I can use on it. I dont have leaf springs on rear I have coil overs so I should be able to go wider. I wanna know what backspace I need on a 15 inch tire , how wide of tire and how wide of rim . I assume a 7 or 8 inch rim Thanks guys:violent1:
what size tire and back space
- Thread starter 68cuda78
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johnparts
Slammed 1
Mini tubbed or not? I'm running a 20x10 with a 295/40/20 with a 2" Minitub.
johnparts
Slammed 1
Well I believe a 275 will fit on a 15" rim. I think an 8" rim with 4.5 backspace will fit nice.
73SwingerBuild
Well-Known Member
9"-10" thread width puts you pretty close to the wheel lip/inner wheel housing.
Centering it is the main issue, and the backspacing needs to be perfect. What rear end? Disc or Drum brakes? Stock axles?
Also, what ride height? The wheel well tapers in, so if your car is lowered, you're even more limited (slightly).
On stock wheel wells with 15" wheels, the widest I've seen is a 255-60. This was on a 14" wheel, but it was close to both the inner wheel well and just inside the fender. You might be able to fit a 265-60 with the springs gone, but it will be VERY close.
At that width, you'll need at least a 7-7.5" wide wheel, and about 4.5" backspacing. It could vary, based on the variables above. Add more details and we'll be able to answer you better.
Good luck.
Centering it is the main issue, and the backspacing needs to be perfect. What rear end? Disc or Drum brakes? Stock axles?
Also, what ride height? The wheel well tapers in, so if your car is lowered, you're even more limited (slightly).
On stock wheel wells with 15" wheels, the widest I've seen is a 255-60. This was on a 14" wheel, but it was close to both the inner wheel well and just inside the fender. You might be able to fit a 265-60 with the springs gone, but it will be VERY close.
At that width, you'll need at least a 7-7.5" wide wheel, and about 4.5" backspacing. It could vary, based on the variables above. Add more details and we'll be able to answer you better.
Good luck.
73SwingerBuild
Well-Known Member
I would put that as a maximum. There isn't too much of a difference between the plane that the spring limits the tire at and the plane at which the inner wheel well hits the tire.
stock axles , drum brakes.... i guess im more interested in how wide of slick and what back space , i may go with some steel rally wheels from summit.. like a 15x7 and run a 26x9 slick. i dont want a tall slick as my gears are 3.23
I might try and run a Mickey thompson et street 26/11.5/15 if it would fit because im gonna drive it to drag strip and i wont have to change tires out there. I had a set on a 8.0 sec ls1 in the 1/8 mile and they hooked fine
73SwingerBuild
Well-Known Member
I've heard good things about the M/Ts, when they're warm (of course, that's when they all work best).
Like I said, 275 is going to be close. The rear ends weren't perfectly centered from the factory, and I'm not sure what rear suspension you're running or what ride height you're at.
Like I said, 275 is going to be close. The rear ends weren't perfectly centered from the factory, and I'm not sure what rear suspension you're running or what ride height you're at.
73SwingerBuild
Well-Known Member
I don't know of any members here that converted to coil overs and didn't do a mini-tub. I'm waiting for one to chime in.
I know that all of my research limited me to a 255/60/14 (at the max) with a 14"x7" with 4" or 4.25" BS. And even this rubs around corners, from what I'm told.
There's not much wheelwell to work with on these models.
I know that all of my research limited me to a 255/60/14 (at the max) with a 14"x7" with 4" or 4.25" BS. And even this rubs around corners, from what I'm told.
There's not much wheelwell to work with on these models.
On a Dart a 275 will fit with a 1/2" spring relocation and a fender lip trim. I jammed a 17x9 with 5" backspace on my '71 Dart with a 275/40/17, it made contact with the stock location springs and the quarter but I was able to get it in there.
With coil overs I'm assuming you have at least as much room as with a 1/2" spring relocation, probably more, so I'd think an 8" rim would work, 4.5" backspace should be about right, maybe a little more for you for some extra quarter clearance since you don't have to worry about the leaf springs.
With coil overs I'm assuming you have at least as much room as with a 1/2" spring relocation, probably more, so I'd think an 8" rim would work, 4.5" backspace should be about right, maybe a little more for you for some extra quarter clearance since you don't have to worry about the leaf springs.
73SwingerBuild
Well-Known Member
A 275 on a 17" wheel is not as wide as a 275 on a 15" wheel. The sidewall bulge is significant on the 15". It will probably run the inner wheel well. Again, he hasn't specified his ride height.
gold68dart
Well-Known Member
I think the 71's have the same wheelwell room as the 67-69 darts. If so, the biggest tire you will fit 255/60R15 with 4.25" of backspacking on a 7" wide rim. That is assuming you do not relocate the springs or fold the inner fender lip.
73SwingerBuild
Well-Known Member
He has coil-overs in the rear, but thank you for confirming my numbers. Good to know I was in the right ballpark.
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