I have a Stock 1987 Iroc-Z that I would like to put TT2's on but im not too sure on the backspacing. Ive been searching on here but honestly im confused beyond belief already. I just need a definite answer before I order. I want to put on 18x8 on the front and 18x9.5 on the rear. Just not sure on the backspacing. What backspace can I run on the front and rear so that it will fit perfect without rubbing or having to mod anything? Any help is appreciated

 

Welcome to the forum. There are some sticky threads on top that have some great info. Personally, you'd want to measure for yourself rather than take somebody's word on it. These cars are old and who knows that previous owners have done in the past.

Check out this link.
https://www.rsracing.com/tech-wheel.html#backspace

 

Do 18x9.5 all around with 5.5 inch back spacing.

These are 17x9.5 all around with 5.5bs

 

18x8 with 4.5 backspacing for the front and 18x9.5 with 5.5 backspacing on the rear will fit perfect with no mods or rubbing.

 

what size tires are you running?

 

Please go 9.5" on all 4 corners please - your car will thank you for it...

 

I don't know who that question was directed at, but the tires on my car are all 275/40-17.

 

Good info. Exactly what we need to know.
Now, do we go with 17" or 18" Torq Thrusts?