backspacing question

[burrpenick]

I have a set of 15" steel wheels off a Jeep Cherokee on my 72 Cuda while it is being worked on. They are rubbing slightly on the top of the A arms- not all the time, but when turning etc. I have not measured the back spacing on those but just checked my American Racing alloys I plan to use that are 15 x 8 and that b/s measures 3.5". Does that sound like it s/b OK on my car?

Thanks,

[Carlwalski]

What tire size are you going to run? I'm guessing it'll be in the rear.
If it were a 245 I would think you'd be fine, maybe not enough BS to clear the lip with 275s+.

I think the consensus is 4-1/2" BS around here works best with 275s.

[miketyler]

I think the consensus is 4-1/2" BS around here works best with 275s

Yup - I think 3.5" will give you a cool deep-dish look on the outside but may put the outside edge of your tire too close to the fender

[burrpenick]

I was planning on the 235 front/255 rear set up. WOuld those be safe with the 3.5 back spacing? Why would I have this rubbing ion the inside edge of the rim and the a arm with the jeep wheels?

[miketyler]

I think you will have problems with such a narrow backspacing but since you have the wheels, why not bolt one on and find out? Even better if you have the tire mounted but if there are immediate clearance issues with the wheel alone, easier to measure and adjust with a bare wheel. I am no expert but too little backspacing is not easily remedied. Too much backspacing and you can possibly use spacers or adapters to correct it.

As was said, I think 4.5 front and 5.5 rear BS is ideal on these cars. I have read several threads where guys are running that with stock suspension and no issues. For your narrowed backspacing, read page 9 of the tire and wheel combo thread and read what Troy has to say about his experience with 3.75 BS wheels. Thread is here:  http://www.cuda-challenger.com/cc/index.php?topic=19470.120     

[HP2]

Why would I have this rubbing ion the inside edge of the rim and the a arm with the jeep wheels?

Because those jeep wheels probably have more than normal backspace. The 5 inches of back space on them that when combined with only a 15" rim diameter, put them smack dab into the control arm. 4.75 back pace is the max you can get away with on the front with a 15" wheel. Move to a 17" wheel that will clear the control arm and you can get away with 5-6" of back space. Then tire fitment becomes the issue

Your AR wheels are the exact opposite with less the normal backspace. This may put the tire into the wheel lip on the rear or have you clipping the front/rear edge of the front wheel opening.