I thought I talked to you about Race Magnum mufflers before. I just got a set of #64 heads for my 455. They'll raise the compression to 10:1 like in a 1970 455. Anyway, do you know what length duration and lift I can get away with? They have been ported and it has a tri-power. Its the 69 Convertible Firebird

Please Scroll Down to See Forums Below 









