i have a 1991 z28. i put 11.5" inch tires on the rear to do this i had to put a 2.5 " spacer on the car. this causes the tires to stick out past the wheel well. every time i hit a bump the tires slam into the body. though much time and money spent troubleshooting i've come to the decision that i need spring spacers to lift the rear end up an inch at least.
the reason for this post is to find out where i can buy spring spacers. and if any one has run into this problem before and have some tips for me please let me know. thanks in advance to all who can shed some light dan

 

Pep Boys has rubber spring spacers. Never had this problem, I stick with tires and rims that fit under the fenders.

 

Might I suggest heavy lb. rear springs and larger bump stops. You might want to try 225LB springs or higher. It will ride stiff as he// with 250-300 lb springs. Most race cars run 225Lbs in the rear.

 

If you're looking for new spring isolators, go to GM. $11 each, and they raised my Iroc about 1.5" AFTER I installed EIbach springs in the rear.

Here's a shot of the new ones next to the old ones. I have roughly 2.5-3" of fender gap in the rear wheelwell now.

Ed

 

air springs. slide them into the spring, fill them up and no more rubbing!! cost ya 62 bucks and you wont have to drop the rear....at least i didnt