I replaced a Volvo MD6A (close to the MD7A) with a Beta 16. Did all the work myself, and I had zero experience with diesels before all this. I have a Seafarer 31 Yawl, which has pretty long overhangs, not only making the engine compartment tight, but also sloping upwards behind the engine.
Here is everything I had to change/accomodate for the repower:
1) The old engine mounts were totally inadequate, so I had to fabricate new stringers, which had to be 2" higher than the old mounts. Not being experienced with this, it took a long time to do this.
2) The Beta transmission is shorter than the Volvo, so I had to replace the shaft with one that was about 6+ inches longer.
3) The propeller on the Volvo was a LH rotation, where the Beta is RH. With more RPM, I used the same diameter with a lower pitch.
4) While I was at it, I rebuilt the shaft log (which had originally been a bronze rudder fixture) using G10 fiberglass tubing glassed in place. I had gotten much better at fiberglass work, so this wasn't so bad.
5) The exhaust hose on the Volvo was 1.5", on the Beta it needed to be 2". Also added a waterlift muffler. Upgraded to a hi-rise exhaust manifold due to the rise behind the engine.
6) I had to replace the raw water intake seacock from 1/2" to 3/4" to match the water hose and fittings.
7) I replaced the old corroded steel fuel tank with a Moeller plastic tank, and replaced all the old copper fuel lines with rubber hoses and added two new fuel shut-offs. Added a new Racor filter.
8) Replaced the instrument panel (upgraded to the B panel)
9) Had to reverse the gear shift and throttle controls, and get longer cables.
Well, I got the boat back in the water. Added fuel, oil, and antifreeze. Connected the battery. Bled the lines and injectors. The thing started right up. No leaks, no unusual vibrations. Much quieter than the Volvo. No one was more shocked than I was. Works great, but it took a few more time of bleeding the lines and injectors before it was good to go.