Swap a 350 small block into a 454 large block boat

[84EdH]

Hi, I saw a 1990 cobalt 252 for sale with no engine. The owner has a built up 454 he wants to keep, including the bell housing. The outdrive is a Bravo 1 which would come with the boat, as well as the transom plate. It has captain call exhaust set up. I have a 5.7 engine from 1995. Is it possible (and feasable), to install the 5.7 where the big block was used? Cobalt shows that boat had a 5.7 power option, but I dont know what all would be involved with a swap.

Thanks for any help!

Ed

 

[84EdH]

Re: Swap a 350 small block into a 454 large block boat

Bubba, thanks for the input. I dont know much about Bravo drives but the 350 engine i have is 300+hp. Do the big blocks produce enough horse power that the 350 would not suit it?

 

[TilliamWe]

Re: Swap a 350 small block into a 454 large block boat

It's the torque that is so superior in a 454. But if you have a 5.7 that produces 300hp, and is not built like a flat track race car engine (low torque/6000+ rpms to get the max hp) then it might do okay in that particular boat.

The Captain's Call exhaust could give you a little trouble, but flexible hosing should fix that.


IF the drive is a 1.5 ratio, you should be able to find a low enough pitch prop to use. That is of course, if your 350 really has the power you think it does.

IF you have ability, time, and money, you could do the swap, and it would turn out fine.

 

[84EdH]

Re: Swap a 350 small block into a 454 large block boat

The engine is a 350 vortec engine, roller cam, high rise cast iron manifold, edlelbrock carb. marine engine. but, I am not married to the boat I described. I have been looking for a good boat with a bad engine as my old boat has turned out to have rotted floors etc. maybe i will just wait a bit and keep shopping.

thanks