Well I've been looking around on this forum today a lot but haven't found any really clear info about this. I've got a TTA with the aussie 9bolt rear with the 16x8" stock wheels. I know of a guy running a 17x10" wheel with a 5.75" backspacing which I believe is a +6 offset.

Does this sound about right? Of course I want to run as wide as I can without them really sticking out and without doing any modifications besides maybe tubular control arms. So can I go any wider? Here's the pictures of the guys car to show how they fit http://www.turbobuick.com/forums/sho...d.php?t=167151

 

I put 17x11 on my 90 Firebird.
They are from my Corvette with a 2" spacer. Fits under the wheel well. (315/35-17)

Search on ZR1 rims

 

yeah I don't want spacers at all. I'm having these wheels made to custom dimensions so I don't wanna buy anything I need spacers for, plus I like the extra lip

 

IMO the best way to find the answer here is either to goto www.skulte.com and read the wheel adapter FAQ for the formulas you can use to do the math and determine your answer on your own, or option number two to do searches on different sized wheels and see what peoples experiences are. So if you are going to go with option number two remember that the width , backspacing, and offset are not related to the diameter. So if you want to fit a 10" wide, it wouldnt matter if you copied the specs from a 16x10 or an 18x10, both would be the same for a 10" wide wheel. So with this in mind, use the search function with terms like "*x11" or "*x10" etc etc to see what specs other people are using. This is how I determined the specs to use on my 9.5" wide wheels in the rear (after doing the math and not trusting myself hehe)