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jrbobdobbs1
03-30-2009, 11:10 AM
I've done some searching on this and it's kinda of "maybe" as to the ability for these to work on a stock height 70 Buick GS. I was planning to use 17 x 11 5.5Bs on the rear and 17 x 9.5 4.75bs on the front using these tire sizes.

Has anyone actually tucked this size into an A-Body stock height setup?

Thanks,
Bob
Racerx88
03-30-2009, 11:19 AM
Re: 275/45-17 Front, 315/35-17 Rear

The fronts will be 26.74" tall compared to a 245/60-15 which is 26.57" tall.
The rears will be 25.68" tall compared to a 275/60-15 which is 27.99" tall.

Height-wise the fronts should be fine, while the rears are probably a little short.

I think the width is where you're going to run into problems.
The front tread will be 10.83" wide compared to a 245/60-15 which is 9.65" wide. That's over an inch wider!
The rear tread will be 12.4" wide compared to a 275/60-15 which is 10.83" wide. That's and inch and half wider!
70 gsconvt
03-30-2009, 11:29 AM
I run a 15x10 on the back with 5-5/8" backspacing and a 325-50R15 tire. It is very tight. With only 5.5" of backspacing, you will probably have rubbing issues on the outer wheel well area.
jrbobdobbs1
03-30-2009, 04:29 PM
Okay, I can see where this could be a problem. It looks like I'm going with 255's on the front with 17 x 8 and 285's on the rear with 17 x 9.5. Any suggestions on backspacing with this setup?

Thanks!
70 gsconvt
03-30-2009, 07:42 PM
With an 8" wide rim, 4.5" centers it in the rear and with a 10" wide rim, 5.5" centers it. Remember that these cars were not built to exacting standards back then and do vary as much as 1/4" in the back.

I would think you'll need 5.5" of backspacing in the rear. You can always shim them out a bit if needed. But you can't "unshim" further in.
pro tour gsx
03-30-2009, 07:51 PM
http://i267.photobucket.com/albums/ii312/gsxser/cecil033-1.jpg
pro tour gsx
03-30-2009, 07:55 PM
They do fit but you may want to trim or roll the rear lips. Mine do not rub at and my car has 2inch drop springs.
jrbobdobbs1
03-30-2009, 08:13 PM
Now that's what I'm talking about. I'm going with 5.5 on the rear and 4.75 on the front.

Thanks for the input.:beer
Nothingface5384
03-30-2009, 09:28 PM
why go with a taller tire in the front compared to the back?
why not a 245-45-17 front with 315-35-17 rear?
jrbobdobbs1
03-31-2009, 07:27 AM
Good point, but after giving it some thought (and discussion here) I'm going with 255/45-17 front and 285/40-17 rear. That's less than 1mm difference and no issues with rubbing (I hope).

Thanks.
Racerx88
03-31-2009, 08:52 AM
Good point, but after giving it some thought (and discussion here) I'm going with 255/45-17 front and 285/40-17 rear. That's less than 1mm difference and no issues with rubbing (I hope).
Thanks.

That makes the fronts 10.04" wide and 26.04" tall. Might work with the right back spacing since they're shorter than a 245/60-15, but might still rub.

The rears would be 11.22" wide and 25.98" tall. Too short IMHO, and possibly too wide, but again, could still work with the right back spacing.
jrbobdobbs1
04-01-2009, 07:35 PM
Using this setup what would you suggest for backspacing?



That makes the fronts 10.04" wide and 26.04" tall. Might work with the right back spacing since they're shorter than a 245/60-15, but might still rub.

The rears would be 11.22" wide and 25.98" tall. Too short IMHO, and possibly too wide, but again, could still work with the right back spacing.