The diesels are sweet. Parker made a few with the Merc's but not many. The block itself is Italian- VM Motori, which is now part of Detroit, but Cummins now handles all parts for merc diesels which is no big deal from me because I used a good factory trained wrench for it. The only problems I had were a spun crank gear in the middle of the tuna season for us. The boat does 2.5-3 NMG and cruises well at 22 knots. It tops out at 32-34 depending on load. My range is about 550 NM. The biggest problem I have is the lack of a fish hold. Some guys with the I/O's chipped out foam in front of the engine hatch and installed one but I use a kill bag that keeps the fish better than a hold. The main advantages I see are the range, durability, safety and torque with the diesels. Some folks don't like the engine box but it makes a great seat and I get around it fine. Boat came fully rigged except for rocket launchers, bait tank, and windless. It is hard to find a diesel Parker period and almost impossible in So Cal. I got lucky finding one and getting it for the price I paid. The engine was not even broken in (138 hours) when I took delivery.