COMP Cams Camshafts 01-602-8 Hydraulic Roller - Big Mutha' Thumpr: Street/strip, needs 9.5:1 compression, 2800+ stall, intake, gears and headers, very rough idle. Big Mutha' Thumpr 243/257 Hydraulic Roller Cam for Chevrolet Big Block GEN VI COMP Cams Big Mutha' Thumpr 299THR7 Camshaft for Gen VI Big Block Chevy BMT 243/257 HRlrBBC6