Originally Posted by Searider
Used Volvo AD41 200hp would go in if engine bay has enough length.
Look at the V8 diesels sold by MDS at Hamble Point - although expensive and usually go on Mercruiser drives.
Or GM 6.2 V8 diesel:
help with a petrol to diesel engine convertion
No easy or cheap options.
The 6.2 engine is a very old lump and the parts are very expensive.
The 6.5 is the better engine, the one I converted for a customer years ago, he bought a 6.2, a set of pistons, rings, mains, big ends and a gasket set was over £1800 (trade), props were changed to what was recommended and in the end had to drop 4 prop sizes just to get it on the plane and then it ran out of revs, all the power is at the top of the engine rev range.