3.0 to 4.3 vortec swap

[Mark St.Martin]

Hello...I am not really new to boating but I am new to this site. I look forward to participating in future posts!
My question...
I have a 94 Thompson that has rotted out floors and stringers. The motor ( 4.3) and outdrive (alpha 1) are fine. I have an opportunity to aquire a 92 Forester that is gorgeous but needs a motor. It has a 3.0. I don't know the outdrive make. I have everything for the 4.3. I understand that a 4.3 was an option for the Forester. What am I looking at as far as a direct swap goes? I am versed in automotive engine swaps but this would be my first boat. Any help would be appreciated. Thanks! Mark

 

[FreeBeeTony]

I think you need to answer your own first question first......what make O/D is in the boat currently to see what mods you may need to make to the transom.

 

[Mark St.Martin]

Yes, of course you are correct. I will quiz the gentleman later on the outdrive.

 

[thumpar]

If the 4.3l is not a Mercruiser you are going to have to buy a lot of expensive external parts to make it work. Even with it being a Mercruiser it is still going to take time and money to make it work. I would not buy a boat unless it had the motor I wanted in it. It is cheaper to just buy a boat with the motor you want.

 

[Mark St.Martin]

The 4.3 is an Alpha 1. If I take the whole works off the Thompson, is it relatively straight forward? The Thompson has literally no floors and basically no stringers. My problem is that I have too much money invested in the Thompson so I would like to use the motor/outdrive on something not rotted out!

 

[achris]

If you are swapping Mercruiser for Mercruiser (including the drive) then it is a fairly easy swap. (I done quite a few)... Depending on the year of the 3 litre, you may not even have to swap the transom assemblies, just engine and drive. You've called the year of the hulls, not the engines.. If the engines match the year of the hulls then they are both Gen II, the hardest par t of the swap will be fabricating side mounts for the V6 to sit on, and making sure the engine cover is wide enough....

Chris....