The 74s also had crush bumpers. They were the split type that only came on 74s. I know of several 74s that have upgraded to the solid crush bumper with no problems. 73 frames were the last of the chrome bumpers.

Bill

you can use 75 to 79 frames with no mods. I am a dealer, and i sell alot of them, as well as build alot of cars. I have never had any issues interchanging the 75-79 frames. If you need one let me know. I have them rolling or bare. Corvetteworks@aol.com