Did a nv4500 transmission come in a 1994 Chevrolet 1500 pick up with a 4.3 engine?

There is a chance, but a slim one at best.

The easiest way to tell is the shift knob reading (L 1 2 3 OD).

The next way to tell is if the transmission casing is iron.

Also, there should be a door on each side of the tranny held by 6 bolts if it's the 4500