I have a disc brake upgrade on my 66. I have 79 Trans AM spindles & 11" rotors, so I know the tracking got wider but I don't know by how much?

I want to use:

225/60 R 15's up front on 15 X 6 Rally's 3-3/4" Backspacing.

275/50 R 15's out back on 15 x 8 Rally's 4-1/2" Backspacing.

Anyone use this combo?

I believe right now the tracking in the front is 1" wider than the rear with the Trans AM spindles, but I'm trying to recall this from memory. So with the backspacing difference, the outside of the rear tires should stick out 1-1/4 more per side than the fronts.

I think this would look good, and I also want to cure the rubbing problem I have in the front. When I bought the car it had 255/60 R 15'a all around on 15 x 7 corvette rally's.

[This message has been edited by ETD66SS (edited 01-23-2002).]

I would keep the 15X7's on the front. The 225's will look better and the 4" BS will keep the tire in the wheel wheel better than the 3 3/4's will. Depending on how bad the 255's rubbed just downsizing from 28" EDIT(actually 27.1) tall tires to 25"EDIT(actually 25.6) will make a ton of difference. As for the rears I don't have a lot of knowledge with 50 series but the profile of the fronts will look better with the 50's in the rear if they fit.

If you can get the 275's on the 15x7's you'll be happier when it comes to matching up trim rings front to back. The 15x7 trim rings will fit the 15x8 rims though they won't look quite right to the owner, nobody else will notice. I thing 15x6 and 15x8 will amplify this and you'll have problems finding rings that look the same!!

Good luck...
Edit: Check out www.tirerack.com (http://www.tirerack.com) for tire height and with and what will fit on what info!!
------------------
...Dennis
The '69 (http://chevelles.com/showroom/fine69_03.jpg) & the '96 (http://chevelles.com/showroom/fine69_02.jpg)
Team Camaro (http://www.camaros.net)
Camaros Limited (http://www.camaroslimited.com)



[This message has been edited by DjD (edited 01-26-2002).]

How about this:

15 x 7, 4" backspacing with P225/60 R 15's up front.

15 x 8, 5" backspacing with P275/50 R 15's out back. The trims rings should fit the same both front and back?

I can get the 15 x 8's with 5" backspacing from Wheel Vintiques.

I'd hate to buy all this stuff and find out I have clearance problems.

Check out this BFG page from tire rack www.tirerack.com/tires/Spec.jsp?make=BFGoodrich&model=Radial+T%2FA (http://www.tirerack.com/tires/Spec.jsp?make=BFGoodrich&model=Radial+T%2FA) pick your size and you'll find all the measurments you need to help you fit some tires.

As for the trim rings the 15x8 5"BS are not made exactly like GM 15x7's with 4"BS. I'm running the same sizes on my '69 and even thought the numbers make you think the trim rings will fit the same they don't. There is about 3/4" at the back of the ring that doesn't touch the rim. It doesn't look bad, it just looks a bit different than on the 7" rim...

------------------
...Dennis
The '69 (http://chevelles.com/showroom/fine69_03.jpg) & the '96 (http://chevelles.com/showroom/fine69_02.jpg)
Team Camaro (http://www.camaros.net)
Camaros Limited (http://www.camaroslimited.com)