Need to replace Chevy 350 long block in boat

[Ronny&BevKing]

I bought a 1983 boat that has a Chevy 350 5.7 long block 4 bolt main in it. Can I replace it with the same motor out of a car?

 

[Bondo]

I bought a 1983 boat that has a Chevy 350 5.7 long block 4 bolt main in it. Can I replace it with the same motor out of a car?

Ayuh,..... Welcome Aboard,...... A dead stock car motor can be used,... with a few changes,....
A Hot Rod car motor, not so much,.....
A truck motor is built the closest to a marine build,....

 

[kenny nunez]

The auto 350 will work but as Bondo said not as good as the marine/truck version.
You will need to replace the core plugs with brass ones. Hopefully the current engine has the marine Quadrajet and ignition otherwise the replacement may not perform right and an auto version is not marine approved.
Pay attention to the flywheel bolt pattern as GM changed from split rear main seals to full circle. You may have to have the coupler modified.
Good luck

 

[Scott Danforth]

I bought a 1983 boat that has a Chevy 350 5.7 long block 4 bolt main in it. Can I replace it with the same motor out of a car?

you can replace the motor from one out of a truck.

however you are only using the short block and heads.

being an 80's vintage, you will need to replace the steel core plugs with brass or stainless, the head gaskets with marine friendly head gaskets. then you need a marine circulating pump and the accessories, ignition, fuel system, alternator, etc. from your old marine motor.

suggest new exhaust manifolds and elbows.

I would look for a 1986 or later block myself (1-piece RMS) and upgrade to vortec heads at a minimum if you have to swap the motor.