I was looking up info on the engine for my 18.5' ultra jet boat and i read at the bottom of the description NOT FOR MARINE USE! Is this just for their warranty reasons? or are the clearences on this motor too tight for marine use? I found one on craigslist that was broke in at GM then sat for a few years and the guy wants to sell it, it has an upgrated clay smith cam with .609 lift 284 duration. I plan on tearing it down and replacing all the gaskets and checking for rust, so every gasket will be replaced with the correct marine gaskets. But if its the piston or valve guide clearence thats an issue for marine use then ill just pass this opportunity up. thank you in advance.