donzi matt

iTrader: (1)

Is this a 350 2 barrel carb motor? If so switching to a 4 barrel and a decent intake should net you close to 300 horsepower. Do some prop work from there and you will probably be pretty happy with the results.

ACrooks69

iTrader: (1)

A performer intake does wonders for a 5.7 holeshot. Won't gain much on top unless coming from a 2 barrel. BTW, I have a dart shp 400 block in my boat. I'm going g blown so I needed a better foundation. I wouldn't worry about a stock 400 block sub 400hp as long as the cylinder walls are thick enough. Simese whatever, BBC are simese walls. We have limitless cooling, don't worry about cooling issues.

That said, 383s are tried and true. Go with good heads and the right cam and you'll be happy either way.

NHGuy

No it's a 4 barrel. Do the performer intake manfolds help? Really?
I'm leaning toward a 383 or 377 with 10 to 1. perfect squish. and pistons that mirror the heads. I figure if I buy the bits or buy em and do it myself, I'm better off than taking on somebody elses compromises or ideas.
I work in auto, I sell and run a shop, but I've never been a pro wrench. I have three very close friends and family who have built engines. All have expressed willingness to advise and walk me through problems. Plus there's here and hotrodders.com and other sources.
I may take a season or two to get the hull detailed enough before I start engine stuff unless this boat gets too slow too quick.
To answer an earlier question, yes it's an alpha so I'll have to control myself. But that's fine, I don't need to win any drag races I just want to be up past 50 or approaching 60 mph when the chance comes.
You know what happens, In 2 or 3 years I'll have the engine built and then I'll be sniffing around for a supercharger. It never ends. Don't yell at me, I know it needs different CR/pistons to be "right"...wish I just had a big bag of $. I know what I'd do.

picklenjim

Friend of mine had one and always had trouble with sand accumulating in the block due to the Siamese cylinders. Finally went to a belt driven Bravo/TRS style water pump and that pretty much took care of the problem.

NHGuy

We are in a clear lake, No one seems to get sand in their motors, although there is a bit around some of the favorite hangouts. I haven't been using the hangouts much but might start to go there more this year. This year I'm day dunking so I might find out about sand.

SB

iTrader: (1)

True - we are mostly rocks, There is a reason why they call us the Granite State.

The sandy hang out spots are mostly deep enough it's no issue unless you bury your outdrive in the sand to act as an anchor...but this usually takes a bigger, deeper boat. I've seen this seveal times at Braun Bay (say 30-40ft boats) - and I give the boat owners a heads up on the possible issues.

If keeping the Alpha, with your new to you heavier boat, I'd go mild on power, where the 400 will have no real benefit over a 383.

If you kept your small Baja, then you could run more powe as the load would be a lot less.

How well would your boat run with 350 or so hp ?

NHGuy

Braun Bay, I used to stand on a rock there to do a slalom start when the state took away the permit for our neighborhood ski raft. Back in the 70's a couple of boats would raft up there and we'd feel bad for the local landowners.
Now there are dozens of boats on any Saturday or Sunday. Too many folks for me. But I have folks all through there to visit so I don't stop at Braun usually.
We like to go out between the center islands to the west of Bear. From there we can visit Moultonboro Neck or the west side pretty easily. And it's a short shot to a store or a snack.
As far as 350 HP. That would be my minimum expectation. I hope a well conceived 383 with 9.6 or so compression can give bags of torque to keep my fat Formula moving. It weighs over 4000 with fuel and load. So if I do a smart build and keep it cool I hope the drive can live long. I don't run a lot at high speeds. I just like to have the ability to do it. If it starts to eat drives I will have to change tactics. But that's way down the pike.

airjunky

iTrader: (2)

Had a local barefoot boat here a while back running a 406 dart sbc with some mild ported lingenfelter heads holley carb cast aluminum wet exhaust vp duoprop.
Absolutely brain distorting lip ripping holeshot en route to high '70's top speeds at about 56-5800 rpm .
And this was pre mpi vortec days .
The sbc has come along ways . The cookie cutter 377 merc rotator should get you 340 to 380 hp depending on your cam and exhaust . The 383 marine sbc went away with the lt-1 block i believe , the vortec block (and heads) generally have less meat on the bone to favor a raw water cooled 383 that can statisticaly last in volume production . (And it opens the channel to save relatively expensive low hour production motors that scored a cylinder ,by just repairing that cylinder . Didnt hear that from me .

airjunky

iTrader: (2)

I knew a guy right up there by you in NH that had a small sea ray going into the '90's running a sbc and alpha ,both heavily modified . I understand that boat defined scary at the time but that guy worked his ass off squeezing every last mph it had . Wonder if he still is around

Trash

Just to throw another choice in the SBC options, look at the Dart SHP 427 short block.