Mercury did change crank mfg along the way. I know the early cranks were Lunati (it was stamped). Later models were not stamped with any mfg name and the Merc part number changed. However it is still a forged crank in all 6.2 engines. It's also the same crank used in the 383 Mag that Merc sells. I've built several with blowers and they've been running for years, turning 6000 rpm.

Not sure what Steve ran into on the Horizon engines, but they should also be the same crankshaft.

Bob Lloyd
Full Throttle Marine

Good to know Bob!

I've bought the last 20 cranks Lunati had. 1 pc rear seal 4340. 3.75" Stroke. 100% USA made. I have 3 left.

I have the crank already, Do have a friend looking though.

Horizon is Mercury inboard high durability line. We took the crank to Steve's custom's crankshafts well known shop in Tampa area. He said it was chinese and he had seen several fail out of boat engines. I think engines are 2005. When the crank went it took block etc. I am very sure it is not a lunati part, perhaps the blue motor was? I was really surprised to see this failure as GM parts are usually more than adequate if used within specs.

Steve