trying to find info on compatability of the bumper and outside skins. that goes for rear bumper also. how well would a z28 bumper do with a sport coupe skin on it? my bigest issue is the rear. all I have is rs and z28 parts cars and want to keep my s/c rear skin and no gfx on this 85 s/c. stock back bumper has good bit of rust

 

The rear impact bar (bumper) Bumper Reinforcement is the same for SC or Z28 ...Mine was showing surface rust. I just ordered a new aftermarket one from eBay. Before I installed it, I liberally coated it with undercoating to stop future rusting. In my case the rear Bumper Reinforcement was not painted completely from the factory. The two outside ends had "some paint" on them. Really just overspray when the car was painted from the factory, as well as the top; but the button where the rust was forming was not painted. My thinking is GM hung the front and rear Bumper Reinforcements before they painted the cars. They "saved" money by not completely spraying the rear bumper?