Camshafts, idle quality, driveability and LSA-REAL WORLD EXP and OPINION

It's a 27' Magnum Marine 24 degree deep V off shore hull. Old school 7000 Lbs of wave cutting fun. The exhaust is 1986 Chrysler Marine center rise iron manifolds that internally resemble passenger side 340 HO manifolds upside down with 3" risers and 4" thru hull pipes. It is a Hughes lobe.