I would do that, but I sold my old crankshaft and my callies crank is on back order (2weeks), so cant verify beyond asking guys who have been there done it. Actually just spoke to Alex Haxby and Mark Rinda, and they both said it's the correct flywheel for my application. Thanks again guys!

bolt patterns are the same gen 4 5 6 ,if the motor is internally balanced you need a neutral wheel

Yeah I realized that, however I had heard the center hole of the flywheel could vary in size. Glad this flywheel will work! Too many projects and parts orders right now, so getting confirmation this would work was a relief. Try working on two boats with a 3 year old! Lol. Good times. But I wouldn't trade it for the world. Thanks again!

Beau, Called me and ask for an explanation of the flywheels. Yes; the bolt patterns are the same. A neutral balanced flywheel for a internally balanced application as Beau is doing is right on track. He could of used his stock flywheel, machined the counter-weights out and neutral balanced it, as he told me what he paid for the billet flywheel it was a NO BRAINER.
If you are using a externally balanced application, the flywheels will make a difference. The early 2 piece style crank has a flange with enough weight that takes away from the the flywheel counter-weight for the Mark IV. The GEN 5 & 6; 1 piece cranks have no counter-weighted flange, so the flywheel has more counter-weight. You do not want to just switch flywheels that are for externally balanced applications, without insuring of the proper application. I always use the appropriate flywheel and balancer for each rotating assy being balanced. If you are using a Fluid Damper that is externally counter-weighted, I always remove the ring and balance with the hub only.