454 Upgrades

I have twin 454's, 1993 models, going t ohave to pull one head cause of a blown head gasket. Thinking of upgrading to roller cam, aluminum intake, and 850 holly's.
Where would you buy these items? Does someone sell a kit?
Also Imco drives, where would you get them, are they worth the money? Are they direct replacements for bravo ones? Would you make the trade?
The boat is a 1993 Profile 31".
Thanks.

All manner of kits are available. I just replaced the cam in my 454 after getting with DuaneHTP over details. Isky kit had cam, Superlifters, springs, retainers, shims, Polylocks, $400 (I stayed hydraulic). I could have gone roller-hyd for $900 :jawdrop: I also put on a Performer RPM Air Gap from Edelbrock. Kept my 700 Holley for now. I'm not a big supporter of roller rockers but a lot of people use them, and a lot of people have larger budgets than I do (2 ex-wives, with extortion payments). I'm running long-slot GM steels, 3/8" pushrods.