repowering an I/O; hp and engine height

[curtis73]

The boat in question is a 19' Baja bowrider getting a full re-do. I just got it and I'm having fun tearing it apart Its the kind where the rear sun deck is full width and above the engine as opposed to a typical box cowl with two jump seats on either side. First of all, for complicated reasons including a handicapped family member, I need to lower that deck as much as possible. Secondly, the 5.0 is wasted and I'm repowering anyway.
- what powerplant might I use to repower this thing that might be shorter so I can drop the deck some? I thought about a ford 302 or an LT1, but that would only gain me about 4" right?
- I'm assuming the 5.0 was the 220hp version. At that I was told it should be good for 60+ mph. I don't plan on going nuts, but I might as well give it power up to its potential. How much power would you guys consider to be maxed? Its about a 2000# boat. How fast do you think it would stay stable?
The boat has a pretty new alpha on it, so that means probably under 300hp and for torque and size reasons no big block. I don't have a photo of mine, but to give you an idea of the hull I stole this photo off the internet:
http://images.traderonline.com/img/6...85553569_1.jpg

[DelawareDave]

I don't think you are going to find an engine with a lower profile that you could install with available parts. Put a 350 in there. Max HP on that drive is recommended at about 280-300. Alpha Gen II maybe a little more.
A low profile intake and short flame arrester should do ya. Get into the engine compartment and close the lid. Then you can measure how much room you really have under it above the engine. Any more than 1 inch above the flame arrester is a waste, in your case, anyway.
Edit: Unless this boat was built in the late 60's/very early 70's, it is most likely GM powered. 5.0 could be a 302 Ford or a 305 Chevy. You don't say which specifically.

[curtis73]

305 Chevy... sorry. Its a 1983. Thanks for the response. Do you think 300 hp is about the max for that hull as well?

[cfm]

As far as speed see top post: http://www.speedwake.com/upload/show...&pagenumber=24
And this is with mild repower. Boat use to run 80 or so with built 350cid and nitrous. It does have an Alpha SS for a drive. This owner and past owner (friends with each other) are very technical and can help you out.
Low good line creates issues for performance. With carbureted engines, The lower the intake manifold the more power you lose / can't make.
So, my vote would be to see exactly how much room you have and this will dictate the engine build up.
BTW: 350hp or so should be no problem with that boat, drive, propped correctly, and a responsible driver.

[curtis73]

Great link, thanks. It looks like I'll run out of need for speed before the boat runs out of capacity. My only real experience with fast boats has been a brief weekend with a 350-powered ski nautique and an older bass boat with a sick 235. So; experienced safe driver, yes. Experience with anything above 50 mph, very little. I think 70 mph should keep my need for speed satisfied for a while. Looks like I might build up a 350 for now unless I find a good price on a forged stroker crank.