dtedesco,
A few things you need to look at are footprint dimensions, Rear foot dimension to coupler flange, height, width, fuel linkage & shaft elevations etc.
I would first locate & download the manufacturer's spec sheet for each engine you want to look at. The installation engine picture & dimensions will help you pick what works & what doesn't. Hell, take dimensions & write them down right on the spec sheet engine drawing for comparisions.
A different make engine could probably have a different footprint. If so, re-drilling might be needed, and this could bring up alignment problems. Could be a lot of work if doing it yourself.
From what I remember, Universal ER, I mean now Westerbeke the engine footprints have remained the same as your original, but confirm this for yourself. I looked at Yanmar (too high), others too long, etc.
When I repowered, from an old 5411 to a 3M30A, I designed SS plate makeup brackets from the engine to the existing locations of the motor mounts at the stringers. Luckily this this worked well for me.
Whatever you decide, just be thorough first.
CR
