I Have a 23 inboard with the 240 Hp Yanmar 4lha-ste with a 1-1.25 zf transmission. That engine if you can find one is about the same size as a small block chevy and a little heavier but not dramatically. My boat will cruise at 23-25 knots and run 29 maybe 30 on the pins. run the same prop as i did with Gas crusader 16x16.
I had seen one with a cummins 6bta but it was really wedged in. the yanmar doesnt require any cutting but i did change i'm i'm up the engine mounts to allow better engine mounts that absorb more of the diesels vibrations at idle.
jim
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