changing out a Transom Sheild

Hi all newbie here on this forum
What i need to know is that how hard is it to change out a out drive and the transom plate
Ive only had this boat for about 12 months now
Ive got a AD41B Volvo Penta Inboard with a 290 sp out drive always in salt water
The transom plate thats on the boat atm has signs of corrosion and the out drive needs overhauling
I have picked up a really good second hand Transom Sheild and out drive, but it was off a 4 cylinder Volvo Penta, Ive been told that it should all bolt on and all i need is to prop size it as the ratio would be different.
Can this be done and what troubles will i incounter
Any help would be Great thanks
COZZA

Here is what is attached. I would worry about your exhaust for corrosion. Mine is fresh water and was almost gone around the exhaust mounting flange due to the diesel fuel and electrolysis corrosion. Make sure your grounds are in great shape while you have it apart. If you have a drive and transom shield from a AD31 then the gear ratio would be the same and your old A props should fit as well. You could try and do the swap with engine in. If the engine is easy to lift out then my vote would be to pull it and do a complete re-install after everything is cleaned up and repainted.

Hi skiss thanks for the reply, well i just found out that the Transom plate and out drive come off a 171c and thats a petrol Volvo so i dont know if its going to work now. maybe just the Transom plate still might work??

If you have both transom shields why can't you just compare them? Take some measurements?
They will both have part numbers cast onto them .