454 build

I have two engines. A gen 5 and a gen 6 bbc454 . Was wondering which one is best to build for my 1970 bubble deck. Both engines have bout 120k miles on them and are not marine but run great. Could I Marinize and use for a while without new pistons n crank. I realize the cranks are not forged steal but thought I could possibly bolt on marine equipment and go a few years before balancing and blueprinting the whole engine. Appreciate any help. This will be a project jet boat

 

Is this the same boat as you were working on 2+ years ago? Got any pictures to share?

I'd go with the Gen 6. 'Marinizing' the engine would include electrical/ignition, fuel, and possibly some exhaust components, depending on how you plan to set the engine up. . . That is if you are going to have an open or concealed engine compartment. If you have 'wet' exhaust, you may need to swap out the cam. If not, then you can go more hi-performance on the cam.

Marine 454 long blocks have stainless steel head gaskets and brass core plugs . . . along with a very mild cam. Otherwise, pretty much the same a truck engine.

 

If they are raw water cooled and have an aluminum manifold, they also have a brass insert in the crossover water passage.

 

Yes it’s the same boat. I’m way to busy buiding a spec house. Hope to get more on it this year though. From the pics you’ll see the gen 6 bbc. As u can see I got the mono stringer out. Have now decided to remove all n put in 2 full stringers. I think I’ll take your advise and change the cam and get a high rise manifold. I’d like to close the compartment but not sure if it’s possible with a high rise. I expect wet exhaust outlets through the transome will be used. I don’t know a lot about speedboats. Just remember sitting on the banks of Lake San Antonio as a kid wishing we had one. Also not sure what to do with the fuel tank fiberglassed into the bow. Concerned bout safety for a fast boat. Seems I should just use it. Got any thoughts on that?