Swap motors, How tough could it be??

[Cut2Short]

Looking to change motors between two boats. The two motors I'm working with are a 1998 Mercury 200 EFI and a 2005 Mercury 225 EFI. The 200 hp unit is a 2.5 liter and the 225 hp is a 3.0 liter. I'm wondering how dificult it is to do, the main concern is with the wiring harnesses and whether they are interchangable along with any other wiring challenges? The fuel systems look similar as does the oil system. Any views sure would be appreciated.

 

[guyjg]

I'm thinking it is a direct switch. You can count the pins on the engine electrical plug to be sure or call a dealer service manager.

 

[Cut2Short]

Thanks for the input, didn't think about swapping the harnesses, I'll check some schematics and see what it'll take. Why do you think it would get expensive, what would I be looking at?