On Nov 3, 1:27 pm, Wayne.B wrote:
On Sat, 03 Nov 2007 10:57:15 -0700, wrote:
I have a 32' Luhrs Sportfisher. Currently with Chrysler 318 engines.
I have 2 Chevrolet 350 4 bolt marine engines, one standard, one
reverse rotation. I would like to find out what spec. and what parts
I need to build these engines to 280 to 300 hp on carburators. The
boat weights 17000 lbs. It is my understanding I need foot lbs. of
torque more than rpm. Anyone know if there is a guide or book? Anyone
with information. Thanks in advance.

The most I've seen from a carburated 350 is 260 hp. You can get 300
to 320 with multi-port fuel injection, maybe more. With 17,000 lbs of
weight you'll be a lot better off with 454s or even bigger. My old
Bertram 33 weighed 21,000 and it was only a marginal performer with
350 hp 454s.

I had 350's with carbs and 300 hp, it's not difficult. A better choice
is to make those 350's into 383's, plenty of torque at low RPM's and
still light weight. Even better, if you can find them, small block
400's. But to do any of this you need a good engine shop that knows
marine engines. Their's so many choices of heads, valve sizes, cam
shafts.

About five years ago I had a shop I've been dealing with for years
build me 300 hp 350's, completely remachined, new sheet metal, pistons
rings cams, bearings timing gears and chain, oil pumps, ect. Bottom
line, $2500 each, I'd probably bet their about $3000 each now. The
best thing about 350's are the parts are cheap!!!