Have 88 24ft monteray open bow with 5.7.
Taking 5.7 out an building 454 for it with alpha 1 outdrive, 23 p prop. Block is ready to add parts.

K I want the boat to run 70 mph +. I have donor parts from 99 baja outlaw 502, have cam,all exh, etc. I did pick up good deal on manely dome pistons????? Any suggestions would be nice on heads etc, have trucks laying around..

Better upgrade to a Bravo Drive

yep, i have a 1994 sea ray 240 bow rider with a 489 ci stroker, 63.8 so far with more to go but the Bravo would be mandatory

G'day mate,
From the sounds of things these boys are right! I've swapped up to a Bravo1 and 454 in my Stinger 222. I think your prop might be a bit shallow too to get up that high unless your building a hard revving 454?
I don't know much about props but I've been advised I need a bigger one than yours for a smaller boat so it's just something to think about.
If you need to rev, the alpha WILL fail. If you're trying to make enough HP in a 454 to hit 70+, you're going to need high RPM or a stroke kit. That or no idle and a drag car engine!
Make sure you get a good strong coupler too, not just your old one from the 350!

I'm sure the lads will chime in though, they've helped me a heck of a lot with mine so far!

Good luck mate,
John

im turning a bravo 1 4 blade 26 pitch

sounds like the alpha not going to work.
K i have a steel crank with eagle rods. Pistons are dome but seems like everyone on here has flat tops..? anyone run a dome?
I have a set of peanut port truck heads? should I upgrade to set of oval ports?
I assume the exh an cam from the 502 motor will be fine for my application?

The peanut heads are not going to do the job for you. You'lll need a set of square ports. You will also have find out what dome volume you have on the piston. You also don't state what the cam is (flat or roller). Odds are it isn't going to get you to your goal. With a 23p prop you'll have turn at least 6500 rpm, and I don't think you have the most eificent hull. Just my opinion.

To get to the 70+ mph mark you will need crank, rods, pistons, roller cam , dart heads & a whipple then put a bravo on it . all that will be left is some one crazy enough to drive it ! good luck

I LOVE it!

I'm running flat tops, the 741 (112 dur) cam and Vortec heads with high comp flat tops and +0.040 in my 454, that having been said, it should be good for 500hp. (I hope!)

I don't know about the cam you've got, but there's a bunch of talk on here (search helps!) that the stock 500hp 502 cam is the Crane 731 cam or 741, I can't remember. Either way, it should be a good cam, so long as you new block can accept it. What year is your block? If it is a Mk V or older (Mk IV) then oyu may run into lifter trouble with the hyd roller from the 502 / 500hp which I believe are Mk VI blocks that have higher lifter valley walls.

Like I said though, quickest and easiest way is to do a quick search on what you're after and generally I find someone else has already asked the question before me!

Good luck
John

just a thought, your adding weight going to a bb and a bravo and your buying a lot of new stuff, what about building a better small block?? I' thinking freshen the bottom end, heads and a little blower running conservative boost would have an old bowrider going faster than it should anyways...