Sorry for the test. Been having trouble posting lately.
The steel liners you bought are made by Goodmark they are nice and should fit OK. You might have to drill a couple of holes because I think Chevelle fender holes are layed out different.
I have new GM liners that I had painted base coat clear coat in black. www.goodmarkindustries.com They supply almost all the repro body parts in everybodys catalog. Get their catalog. It has a lot of stuff.