my buddy has a 1990 7.4L 330 hp, he was wondering what can he do as far as bolt on mods to give it a little more juice. any suggestions for cam, intake, heads, etc.. would be great

The 330's had peanut port heads, cast internals, and wimpy cams. Not the greatest foundation for making power. However, a head upgrade, cam, roller rockers, intake and carb would wake it up big time.

any suggestions on a cam kit and heads and intake? anything anybody has tried that is proven?

BROWNIE RACING ENGINES-

Matthew Brownie, builds engines here in VA and knows his stuff!!! I have the same engine, only it's a '96 and we just talked a week ago about what we could do this winter to wake it up! If interested in talking to him, PM me and I will get you his info! This guy has factory reps calling "him" for advise. Great guy and a heck of an engine builder!

try to find a set of 781 large oval port heads, a RPM air gap intake, good marine profile cam, either a 750 or 800 DP holley and should be mid 400's hp

really need to figure out where you want to be HP wise. I'd probably go with the cam that came stock in the 400 and 420 mercs. Its a crane cam. Edelbrock air gap intake, some roller rockers. If you have a quadrajet carb it can work on a mild build like a 400HP engine. You can always pick up some used rect port heads that came on the 365HP and up merc motors if your on a budget. Ovals would be a better choice, but not absolutley necessary. Keep the wot rpm 5k or under with the cast internals of the 330. Better exhaust manifolds sure wont hurt either.