Going to pick up a second boat this weekend and I'm really considering keeping my current boat as well. Both boats are small block alpha rigs and I would like to turn one into a real beast by upgrading to a BBC. What all do I need to convert from alpha to bravo? I know I need transom assemblies and drive and what not but I'm not sure what else is needed. Any input would be great

i did a small block to bb swap. stayed alpha. needed different power steering-alt bracket. diff exhausts. flywheel obviously. made do with everything else from the small block.

I'm talking 500-600 hp range. Alpha ain't gonna cut it

What kind of boat is it? Unless its something special I would punt it and take the $15,000+ its going to cost you do do the swap and build the engine and put it toward a boat that already is fast. There are a lot of good deals out there for $20,000. You could most likely get a 27 Fountain Fever for than kind of money and that boat was designed to go fast.

It's either going to be my 20' Concord Magnum II or my 20' Concord Mach III. I am limited to 20' on my lake so something bigger is out of the question. I know a guy with same boat with a Volvo dpx and a 502 that runs in the mid 80's. Another guy has one that has a 350 mag efi and a black hawk drive that runs mid 70's. I'm currently running low 60's with a warmed over 350 and an alpha. I'd say a 500 hp bbc would really get this thing humping.

http://www.concordboats.com/Magnum-II.html

http://www.concordboats.com/Mach-III.html

I'd be careful putting to much power in that boat. Its really light and at 80+ mph it isn't going to take much to get you in trouble FAST. Better plan on adding external steering as well, at those speeds it's not an option.

Either way here is what you will need. Bravo Drive (low hours only) Inner and outer Transom assembly, Bravo engine coupler, bravo Trim Rams. In addition to the BBC you'll need a good set of aftermarket exhaust, Gil, Stainless Marine, CMI, there are lots of others. Personally I think a stock 502 would be more than enough for a 2500 pound boat.

Hydraulic steering is definitely in the plans. What will I need as far as sea water pump and what not? Should I maybe find a junked 454 and peel the accesories off of it to use? Starting to think that somebody else's 502 take out may be a good option. Just bolt it all in and go and do away with the guess work and head ache

Yes- You'll need a bravo sea pump as well.... I would just run a bone stock 502 and stock exhaust, it will save you a ton of money and your boat is still going to be wicked fast. Your going to be faster than the one running the a volvo drive.

Thanks for all the advice. Definitely going to start shopping for takeouts and used drive components. Now I just have to figure out which boat it all goes in lol

Almost forgot, what will need to be changed as far as wiring harness to hook the engine to the rest of the boats electrical system? Will I need to throttle and shift cables? Will my current gauges be compatible? Anything else I may be forgetting?

Hi,
smokin' gun here on oso has a 454 mag in the swap shop i think