Footprint for the newer Yanmar is slightly smaller. The mounts were in the same positions so no new reconfig are necessary,
Actually the newer Yanmar is about 2 inches longer and the exhaust is on the right side where as the older 3GM30 is on the left when facing the engine(s). Fitting the 3YM30 would require some (major) re-cabinetry changes in our vessel.
I agree the Beta may have been a better choice..