Flywheel identification

It would really help to know what you're working on- big block, small block...
There were externally balanced versions of the 440 Six bbl. and Magnum, the '72/'73 340; and all 360 LAs and 5.9 Magnums were externally balanced. And each one was different, no two are the same.
So, depending on which engine you have, there could be a myriad of combinations that would cause improper balancing outside of the simple internal/external issue.
Plus the fact that there are unscrupulous/uninformed vendors that sell what they claim are flywheels for 360 LAs and 5.9 Magnums- since they are distinctly different balances, who knows what they actually are for...
Mopar Flywheel NEW 130 Tooth 10.5" Cl Pass Trks Dodge Chry 360 5.9 Magnum 13" OD | eBay