Hi, I got a 79 I'm restoring and just about ready for paint. The only thing I dont like is the front bumper. What do you guys do when they are so wavy? I tried to find a decent one on craigslist and e-bay, but just cant find a decent one. Are any of the new ones any good and do they fit? How but the fiberglass ones? Has anyone tried them? Just dont know what to do from here. Thanks

 

Being familiar with the common "urethane warp" on C3 Vettes, I know what you're going through. My old 79 had a fiberglass rear bumper, and it looked way better than a urethane one would. If you go that route with your front bumper, remember it won't be as forgiving as the urethane one if you tap a parking curb too hard.
Here's one source for a glass bumper 1978-81 Fiberglass Bumper Cover

 

I wonder if I can level out the top where the 2 flat flat parts are with flexible finishing filler. would be 1/8 thick or less. Or when sun is on it, it would do something real stupid. Just wondering. Craig

 

I think you might be better off taking a strip of metal, bending it to match the contour of the body, and attaching it to the back side of the bumper with body panel bonding adhesive. Then "fine tune" the bumper once it's bolted on, before you paint.