21eagle

iTrader: (1)

i have a 350 magnum carbeurated. i t is stock i would like to get more hp out of it ???? steer me in the right direction where is this motor lacking??? cam?? carb??? exhaust??? intake manifold??? thanx a lot chris

Nova 26

It comes with the wrong crankshaft- stroke it to a 383.

21eagle

iTrader: (1)

what else has to be done after changin the crank to make it run right

Edward R. Cozzi

Exhaust will show you a big change if you're running stock cast-iron stuff now.

Engine modifications work best if the parts you change are made to work together. You are only limited by how much you want to spend, how much reliability you are willing to give up and how much more fuel your new horsepower will burn.
Will your outdrive be up to the task? You may also need to upgrade your steering. There's much to be considered if you're going to do it right.

21eagle

iTrader: (1)

Can a 1989 350 magnum handle a low boost supercharger any idea if this would work. thank you chris

Ryan00TJ

iTrader: (8)

My Challenger would run around 60 stock with a 260hp 350. I upgraded the exhaust and intake and would then run the the low 60's. I now run AFR heads, roller cam, intake, exhaust, roller rockers, and carb in the 70's GPS. I'm building a 385ci stroker over the winter for more speed.

What I am trying to say is it's all about combo. Just doing one thing or the other will not net a large gain it's a combination of parts to work together to make power.

Big Block Billy

Get a stock 330 Hp 454. The torque is the real difference. Change the gears in the upper drive go up about 2 pitches on the prop and hold on to your seat. These motors are getting cheap due to Diesel repowers. A much better option than to waste money on a blower for a small block marine application.

captnjak

Yep. And if you don't try to wind them too tight or squeeze every last horse out of them they will run forever.

21eagle

iTrader: (1)

the outdrive is an alpha can i change the gear in the alpha? and what would i change it too. Also 2 pitches on the prop would not be enough would it that big block only turns 4600 i have a 21 so with a 23 at 4600 i would only gain about 3-4mph thanx for the replies Chris

Big Block Billy

1.32 gears in the upper. They came stock on boats in the 80's with 454's And alpha drives. They get a bad rap from inexperienced drive builders and people that don't know how to operate a boat. They will take over 400 Hp but must be built without shortcuts, specifically shimmed and preloaded properly to factory specs.
I know , I ran 'em and am setting up another boat with one soon. Actually the drive has survived several blown up motors in 2 different boats.
The boat it's going in is a 21' Lazer Baja hull with a stock 330 454 with some slight mods.
I never Gps'd it but it ran well with a 23 Mirage at full trim to 4500. A real fun boat highly suggest the combination. And as stated, it will stay together, the motor is alot tougher than a sbc, and is not working super hard and stressed alot less. BBB