Engine swap

[Dave15]

Hello there,

i own a '86 c20 with 350cui 165hp and a th400 trans.... now i just got an offer for a 350cui 4 bolt 300hp boat engine with adjusted edelbrock carb.
is it technically posible to change it?
i know i definitely have to change the cams due to the fact that a boat engine has other ones not suitable for cars.

 

[JKRamsey1991]

As long as it is not a reverse rotation marine engine it should swap in. Id try to find the specs on the cam before assuming it needed swapped as well. Swap everything over from your engine (water pump, pulleys, exhaust manifolds) and you should be set. Id definitely try to wash out as much of the cooling passages as possible. Marine engines can sometimes be nasty.

 

[75gmck25]

You need to get a little more info on the newer engine.
- GM went from a two piece rear main seal to a one piece (less likely to leak) on newer engines. Both will work, but the flywheel has to match.

- if it still has stock heads they might not be much better than what you already have. The extra power may be coming only from the cam and better tuning. Even GM has a crate 350 rated at 290 HP. It’s not really a great engine for a truck because it has stock heads and its power comes from a 222/222 @ .050 cam that needs rpm. Down at low rpm it’s relatively a dog, and gas mileage is poor for cruising.

 

[CountKrunk]

Junkyard digs put a mercruiser in an old truck. Dont remember if it was chevy or ford, but go have a look at it.