Originally Posted by 76GMC1500

Turbinedoctor, except for the head gasket and freeze plugs, there are no differences between an automotive 350 Chevy and a marine 350. *The newest of the new marine motors from GM have hardened exhaust valve seat inserts but are otherwise identical to their automotive crate motor equivalents. *Most automotive motors come with brass freeze plugs, anyways.

The accessories are what make the difference. *Marine carburetors have bent float bowl vents that dump the gas inside of the carb as stated earlier. *All marine electronics are ignition protected. *Marine distributors do not have vacuum advance. *Marine ciruclating water pumps have stainless steel impellers and shafts. *Marine fuel hose has a low permeability to fuel vapors.

Everything else is interchangeable between automotive and marine.