I replaced the marinised Ford slant 6 that came with Boracay with a John Deere 4045D with ZF63 gearbox
. The engine
was a bit bulkier, and required a 4" exhaust
and rather different engine mounts, but otherwise fitted OK.
The engine has not missed a beat since it went in.
The turbocharged version (4045T) could be the one you want. The ZF63 was overkill, but there were a few reports of gearbox
failures at the time so I went a bit extra. Their tech support or ZF should be able to advise.
The John Deere technical support was excellent. You may be able to get someone in the states to set it up for you.
Their dealer locator had :-
CALZ. GONZALEZ GALLO # 2500
COLONIA EL ROSARIO
44890 GUADALAJARA JALISCO
as your closest marine