My 283 was built in 1969 and they put whatever yall called back then a "full racing cam" with solids lifters. It had 461's on it also. My compression was 60 psi before i pulled it down. Went back with original std bore flat tops(motor has hardly any miles on it since 58), comp 280 cam (.480 lft)accel elect dist. headers holley street dom single plain "all i had laying around" and shaved/reworked 305 truck heads and an edleb 600. With open headers it sounds 3 times as tough as it actually is. Will turn 7K and runs 15's@95 in my 55 210.