as I posted there can be gear ratio differences if there is a W on the tail housing of one and not the other.
The internal wire harness can be different. Are both harnesses regular wire? Not wires in a hard formed plastic enclosure.
The plug in connector is the smae shape, the pin locations the same on these different trans designs. the wire setup quite different if the wire harness inside is in a hard formed plastic enclosure, not loose wires in a conduit type enclosure
Dont worry how old you are... it is the mileage on your body that adds up.