4.3L to a 5.7L swap. Anyone done it?

[ChrisCraftJohnny]

Has anyone here swapped out a 4.3L V6 Mercruiser with a 5.7L V8 Mercruiser?

I would expect the engine mounts woud have to be moved some. My boat had the option for the V8 and I know there is plenty of room. But is it a do-able project or just a huge pain in the butt?

Johnny

 

[180shabah]

Re: 4.3L to a 5.7L swap. Anyone done it?

You will nbeed to move the mounts forward, replace the ignition module and distributor cap, and you may need to regear the outdrive, but maybe not. What is your current drive ratio and what prop are you running?

You will also need a little more gas money for the first year or two, until the novelty of an extra 100hp wears off

 

[Bondo]

Re: 4.3L to a 5.7L swap. Anyone done it?

But is it a do-able project or just a huge pain in the butt?

Ayuh,... Depending on the direction you take,...
It's more of a Major Expence than Just a pain in the butt...

 

[zbnutcase]

Re: 4.3L to a 5.7L swap. Anyone done it?

Its pretty easy, actually....just start peeling off the $100s and I will tell you when to stop! 'nutcase

 

[TilliamWe]

Re: 4.3L to a 5.7L swap. Anyone done it?

Has anyone here swapped out a 4.3L V6 Mercruiser with a 5.7L V8 Mercruiser?

I would expect the engine mounts woud have to be moved some. My boat had the option for the V8 and I know there is plenty of room. But is it a do-able project or just a huge pain in the butt?

Johnny

Doable, and not a pain in the butt, if you buy a complete Mercruiser 5.7, and have mechanical ability. My father did it on an 89 Sea Ray he owned. The "only" issues he had were that the fuel tank was in the way of one of the front of the engine accessories, and the exhaust hoses were a little hard to get to stay on the Y-Pipe. Moving the engine mounts was easy, since his were just lag screwed into the stringer and there was sufficient stringer ahead of his existing ones to move them the approxiamtely 4.4 inches it will take. He did not have to re-gear his outdrive, but it did take a 25 pitch prop, which are not common.

Big pain in the butt if you try to piece it all together, one part at a time.