Engine swap

[Mrsearay]

Hey all I’m new here, and relatively new to boating. But I just bought a 1996 sea ray 250 Sundance with a bad engine. It has a mercruiser 350 in it now. My question is I found a mercruiser 7.4 for a decent deal with low hours, am I able to swap in the 7.4 instead of the 5.7? I know for the year of my boat they did offer it in the 7.4. Just ain’t sure if a lot has to be changed? Or not to much? And it also has a bravo 3 outdrive. Any input would be greatly appreciated.

 

[Scott Danforth]

welcome aboard

if you have a bravo, you could swap to a complete BBC bobtail

you also need the y-pipes from a big block as the motor is about 4" wider than the small block

or you can also go to a 6.2 liter long block and just swap the 377 for the 350 which would be the easiest

 

[Mrsearay]

welcome aboard

if you have a bravo, you could swap to a complete BBC bobtail

you also need the y-pipes from a big block as the motor is about 4" wider than the small block

or you can also go to a 6.2 liter long block and just swap the 377 for the 350 which would be the easiest

I also have a 1989 maxum with a 454 mag, but it has a cracked block. So I should be able to use those manifolds risers and y-pipe. Will that be all that I need?

 

[Scott Danforth]

I also have a 1989 maxum with a 454 mag, but it has a cracked block. So I should be able to use those manifolds risers and y-pipe. Will that be all that I need?

no, different generations of drives, transom shields and motors

your 1996 Searay should have a Gen VI motor with a post 1992 Bravo

your 1989 Maxum may be an alpha drive, the motor is a Mk 4, and the drive/transom shield, etc. are pre 1992