What are the differences between a marine bb and car bb

[Che70velle]

I worked in an race engine shop in the 90's that built quite a few off shore racing engines. They were big block chevy's, and as mentioned above by db z28, virtually no differences. If I were doing it for myself, I'd go aluminum heads for the weight savings. Cam choice is crucial in a marine app, as you are looking for torque. A lot of high end boats today have LS2's or LS3's in them.