68 Dart blower motor identification

Somebody swapping stuff thru the years likely hence my confusion ordering the motor.
I like the smaller blower motor for non ac cars to have more clearance for my 383 valve covers. I know there is a blower mod thread too to get more room. I was planning my next engine to be a 383 instead of the taller 440 and slightly heavier motor. I will have to research more what I have for heater parts non ac heater setup versus ac. I thought something was weird when I dropped the heater box there was a three prong electrical plug not attached right where the fan resisters are and there was two other wires for the resister. The way it was wired it could not run three speeds only high resister bypassed or low thru the resister. Again likely a mismatch of parts thru the years. Not a big concern we only need heat to extend drivers season.