Wrong Backspacing??
 

I read on another post that it says if you use a ls1 10bolt, you need to use the 4th gen backspacing wheels. The car I bought came with a 10bolt and these wheels. They seem to stick out further then I would like. Is this the wrong wheel for this setup? Im trying to get a 28x11.50 on it and i think it will hit the fender since it seems to stick out. Can anyone tell by this pic? Or does anyone know what the correct backspacing should be to tuck the tire in the fender w/ a 10bolt on a 15x8?

fyi.. i did try to search but i cant find the search button on the new skin.

you are trying to tuck a 28x11.5 tire... with no body modifications? good luck, a 295/35 on a 10" rim needs body modifications to tuck the tire.

save time and money get yourself the right wheel and tire combination. larger tires like that aren't necessary and if they are for your application you would have made body modifications by now.

to answer your question though yes the factory 4thgen rear is 4" wider in diameter. you'll need to adjust the rims accordingly.