[Prowbar]

The idea of a ring instead of individual tabs is a great improvement. I never measured my locking plates, the .080" was a guess, you're correct about the .060" thickness.

I believe all 6 bolt cranks use the same pattern. If the flywheel is zero balance, ie. no added offset weight cast into the flywheel, the bolt pattern should be symmetrical. That is my assumption.

I checked this but will recheck this tonight on my 305 to be sure.
The 305, 351, and 401 are all internally balanced, so the flywheels should swap over without issue.

Hope we can get this sorted out.