Crankshaft Pulley differences?

[vtdeucedriver]

On one engine, I have a pulley with 6 attachment bolts. I have another engine with 4. Anyone know the difference? Is the 4 a civilian crank?

[RMS]

Chrysler made many variants of the Lhead to suit different applications car, truck, marine, industrial.... however to my knowledge the crank is not different. the pulley boss connected to the end of the crank has a key-way and is held on by the crank bolt. the boss varies depending on the application, some have 4 or 6 bolt boss to support the pulley. others have no boss and the pulley bolts direct to the crank. Chrysler crown marine motors have two gears and a bearing on the end of the crank.

hopefully someone will jump in and add to this or better yet, set me strait if I have it wrong.