383 Harmonic balancer question

Be careful here. The 1971 383 non HP engines had a cast crankshaft that will be externally balanced and require a balancer to match.

They are easy to identify = there is a large amount of Side weight present on the Balancer.
Out of the Millions ( I think 8,000,000 of 383 ) I believe that well less than one in a hundred
had the cast crank so the are not real common. I am not sure they had the same Design and
Diameter on the snout. I have not seen one for 40 years.