I'd like too know if any of are tech guys around the forum have did any up grading too the older 454ci motor"s 330hp like swapping out the peanut port heads too oval or rectangle port or installing a newer 454 mag camshaft or after market cams with same or close lift or duration, intake carb set ups, and your experiences with doing so, i'm not talking go fast boats and big rpms or hot rod car stuff, im talking bigger heavier fishing boats.single or twin screw.?