So I'm sitting here with two Windstar 3.8 engines and their respective Harmonic balancers on the ground next to them but not necessarily.... foolishly parts got moved around and now I'm not sure which unit
went to which engine. They are different in that one is SPN 002666 3A and the other is SPN 002666 4A and their respective balancing material volume is different how can I find out which went to which

The only numbers they have don't match what I'm seeing.... now I've reasoned that the numbers you'll see in the picture are stamped into the grooved pulley portion of the assembly while the harmonic balancer is detachable--as is the crank-trigger ring but maybe of a different ( independent) number. I cannot see any other numbers than what's shown on the second photo. So they're confirming now that the new superseding part numbers are indicative of the entire unit but can't tell if that was how they were warehoused originally. They may have been numbered separately. Yeah I can't believe I made such a crucially damaging yet quick and easy mistake mixing these critters up.

As they don't stock the part in there local warehouses anymore I'm required to purchase a replacement unit in full just to have them ship it to my home or local dealer's parts department before I could even stare and compare. And of course this holds value only for the known VIN matching engine.... which is ok as long as there's some indication that it would be the same as the original