I have an 86 EC and I am looking at putting a set of 18" x 9.5" with an offset of 57, corvette C5 Z06 wheels under it. anybody tell what kind of mods I will need to do to get them to fit, and is it even worth it? Thanks in advance!!!

I was looking into the same thing a few years ago when a local junk yard had a set for sale and I was told you would need wheel spacers to get the wheels out further. This would mean adapters. That should be all you need.

Probably a minimum of a 2" adapter....not spacer. The 2" would be for regular C5 wheels and about the max that you could run on a tire would be a 245.....once again....this is for regular C5 wheels. Your experience may vary.....LOL
Craig

PS - try this thread from the Monte Carlo SS forum....it has pics and information that you may find useful
http://www.montecarloss.com/community/ubbthreads.php?ubb=showflat&Number=739948&page=1

Thanks for the info and link very helpfull!!!