165HP Inline 6 Chevy 250CI

"How about some tips on rebuil

"How about some tips on rebuilding my 165HP 250 6cyl. I would like to get a little more HP out of it. Any ideas on cams and fuel systems? It is in a 1973 Larson I/O. Any help is appreciated. Thanks,Paul Hulteng"

"So you beef up the engine and

"So you beef up the engine and blow the outdrive! I/O's do not have a transmission like a car so one gear gets you out of the hole, cruising, and top end. Mess with cams, compression and carburetion to get high end power and you lose hole shot on the low end. Well -- I'll just put a lower pitch prop on you say. Well -- that costs you on the top end so the net result is you spent a bunch of money to gain nothing. Rebuild it with standard parts and have a nice reliable engine. But there is always the 292 truck engine which is the same basic block."

Thanks Dick. Would an atomotiv

Thanks Dick. Would an atomotive block be the same as a marine block?

"A 250 chevy is a 250 chevy. H

"A 250 chevy is a 250 chevy. However, the marine version will have a bunch of different pieces since it doesn't have a closed cooling system. Head gaskets, water pump, starter, alternator, distributor, and cam all come to mind. The crank may be forged rather than cast as well. If you don't use marine parts where needed, those parts will quickly fail due to corrosion. Generally a truck cam is close enough to a marine cam that it is often used."