I'm going to add a front spoiler on my 77 280. It's understandable that polyurethane is a better option than fiberglass due to its resistance to cracking(?). I like the bumper-less look, but am a little concerned about the absence of a bumper. Are there kits available that utilize a bumper behind the spoiler? What can I expect to pay either way?

My only experience with air dams and spoilers is with msa. They have several options for your 77 both fibergalss and urethane. Prices are in the 140 - 290 range.