ugg, i cant believe im asking this, i know people here run 10" even 11" rims on the rear, with 5.5 bs, and they fit in the wells right? i have 8's with 4.5 bs on the rear and im looking to upgrade. i just took a couple quick measurements and as it sits now, the outside of the wheel is even with the inside fender lip. so even if i put a wheel on with 5.5 bs i could only run a 9" wheel without it hitting it!?? am i missing something here? the only thing i have changed on the axle itself is a ls1 brake conversion, but that cant be affecting the spacing? I though i had this whole wheel fitment thing under control and now im lost. anyone?

can someone here just tell me that im going nuts from sleep deprivation and a 10" wide wheel will fit fine.

 

I am running 17x10.5" wheels on the back. The wheels are 4th gen wheels having 58mm offset. I am using a 1.75" adapter from Andea Skulte (sp).
If I am not mistaken, a 58mm offset is about 7.7" backspacing.

I posted on this matter about 2 months ago, do a search.

 

Backspace and offset are 2 different things. Backspace is how far in the mounting surface of the rim is from the inside lip. This is what determines how far in or out the rims sits under the fenders. Offset is a measurement how far that mounting surface is from the direct center of the rim. Backspace and offset are hardly ever the same.

Your 8" rims have 4.5" backspace. When you switch to a 10" rim with 5.5" backspace what you're doing is adding 2 more inches to the rim width but tucking the rim an inch more inside. The outside of the rim will only move outward another inch. The rim will fit with no problems however your tire choice will determine if there's a clearance issue or not. A 28 x 9 slick will fit with no problems however a 29.9 x 10.5 slick needs a bunch of inner fender modifications.

There are many third gen owners with 10" wide rims with 5.5" of backspacing. They can advise you on what street (DOT) tires fit best.

 

thanks for the input, i forgot to mention that im using 18" rims, so im not running slicks, im just a little confused because i put a straight edge on the wheel, and its almost flush with the inside of the fender lip, if it gets set out another inch, it will be even, if not sticking out a little from the wheel wells. i did a little more research, now that the search function is working again, and found a little bit about how, with and 18" wheel, you can use 6" back spacing in the rear. im going to have to look into this a bit further this weekend.

 

5.5 bs on a 10" rim with a 295 will have your tire sitting flush with the outside of the fender. This will require rolling the fender lip. I say go with at least 5.75
I have 6 1/4 bs and I still rolled the fender lip because it's close. I also had to do a bit of hammering and grinding on the inner fender well. Check out the pictures I posted in this thread.
https://www.thirdgen.org/forums/susp...eels-saga.html

 

hey, good batch of pics there, thanks! i had some rust issues with the lip that runs around inside of the wheelwells, you bent then in, i cut them off and made them a little more flush, so i dont think this will be that bad, thanks again