Bravo 1 lower interchange???
 

New to the hotrod boating world. With a Bravo 1 upper, what lowers will interchange? I've got a Baja 220 Sport which has 15° dead rise on it. Currently prop shaft CL is 8" below. From all the reading I've done I can't help but think that making that shorter would be an improvement. Since everything is apart right now it could be as good a time as any to go ahead and make a change.

What’s the power, what does it run now ?

Wish I could completely answer that. Bought it with a few lack of maintenance issues. Had to replace gimble ring, brg, steering pin etc. It was loose as a goose everywhere. I don't think it had anything done to it in years. The 23 Mirage on it has been worked on at least twice if not 3 times(probably repairs)s. The skeg has a chunk out of the front of it. Currently in the process of finishing the back half of the floors. Stringers were solid. Bottom of boat was absolutely filthy. It ran ok considering nothing was in it's favor. With the existing 330hp 454 MAG on GPS was 62.4 @ 5000rpm. Others with same boat in good condition seem to be running near 70 at less rpm and a prop that hasn't been repaired/messed with.
Building a 4" stroke BBC that will make around 575hp @ 6k give or take a couple.

Take all of this with a grain of salt...but... I think you are going to run out of hull with that kind of power. First off a 454 mag has 375 hp. You could probably put a mild 383 at 400 hp or an LS and a 2 inch shortie drive and be in mid to high 70's. if thats too short you could put in a 1 inch spacer. Probably cheaper than the 575 hp BBC.and safer Above 80 that boat will be a handful. 25 mirage plus would be a good start for my suggested setup

Chris

In '87 the 454 MAG was only 330hp. Cast crank, 3/8 rod bolts, tiny heads. New/Used BBC parts are cheap. Much cheaper than switching the full set-up to a small block. Plus I can sell the existing engine for most of what it'll cost to finish off the new build. (I have lots of connections in the drag racing world. It makes building power relatively cheap. If I could find manifolds and risers I'd put my 600hp Olds in it.) I've already aquired Gil manifolds. Dual ram external steering will be added. I'm hoping smaller prop at higher rpm will minimize some of the chine walk issues. It's a hotrod. If it won't handle it I'll move to something a little bigger. But I want to give it the best shot possible. It's just too pretty not to be fast.

Most of those 330 hp 454 “mags” were mated today alpha’s also. I’ve run a few of that vintage bajas’ they all liked a -2” lower. Reduced chime walk and porpoise a lot

It originally was an Alpha. Got swapped over somewhere around 2000 according to previous owner. That's the kind of info I was looking for. Thank you.

Been thinking about this alot. Since I'm not shooting for the moon I'm going to just raise the engine/Bravo 1 2". It's not that big a job. I'll make a 1/4" plate to put between outer mount and hull to cover the existing bolt holes and bottom of existing key hole. That way if I should want to go back it'll be straight forward.