[Baron Von Zeppelin]

Seems like I have heard about different size registers for flywheels before , but I don't remember how the story goes .

Did you ever go through all the date code drills on this new-used engine to ID the block and heads ?

Crankshaft should have more numbers in the casting number than what you posted.
At least 7 digits
After you get all your dates and numbers nailed down , you could post the question in the "Street Section"