wheel tire specs for CMC?

Lj289 · #1 (**permalink**) 03-22-2008, 11:36 PM

Hello everyone, I am new to the board here. I have a Classic Motor Carriages Cobra my father left me and I'm trying to find some different wheels for it. I know the car is using a Mustang II front suspension and a rear from an 89 GT. I would like to get 17x10 on the rear and 17x8 up front but I have no clue as to backspacing or offset and recommended tire size. Anyone with any info would be appreciated. Thanks John

52chevyred · #2 (**permalink**) 03-23-2008, 10:45 AM

John: do a search on back spacing or offset, there is plenty on this sight.
Most wheel manufactures have a website that explains it, usually with a chart.

I have a Street Beasts with 6 1/2" wide rims that have 5 1/2" back spacing or offset to the inside. About 4 1/2" is all I can really use, so I have a 1" spacer on the face of the axle. The tires/wheels I have on it now are just for rolling around in the shop, not driving.

You'll have to see how much "clearence" you have available. You may not be able to put as wide of a tire as you want. good luck!

Lj289 · #3 (**permalink**) 03-25-2008, 01:32 PM

Thanks, it looks like I'll be pulling the wheels off and measuring the distance from the hub to the inner fender. Is there anyone here running that wide of a rear on theirs? I did bolt on a 93 Mustang Cobra wheel last weekend to see what I was dealing with and it seemed to look fine but I believe they are 17x8 and the tire was 235 45 17. It looks to have no problems up front just not sure that a 17x10 is going to work on the rear but we will see. There is definately alot of great info on this site, I'm sure I will have more and more questions throughout the restoration process I will be going through especially when it comes time to beef up the 289 that's in it.

nevermind65 · #4 (**permalink**) 03-25-2008, 03:32 PM

With a fair amount of modifications, you can put a 315/35/17 wheel on the rear. I had to remove the rear spring perches and use coilovers along with changing the coilover mounting positions. Besides that, an 8" wheel looked to be about as wide as you can go. The manual actually states a 7" wheel is all that you can run on the rear, and a 6" wheel upfront.