Classic/Antique Car Repair: Saginaw 4 Speed Trans, chevy impala ss, 1963 chevy impala

Question
Have Saginaw 4 speed trans with stampings on pass. side - GM6
389985K - N92 - on tail 362254 Also bell housing has 3840383 on it. Can you identify year manufactured, where, make & model of vehicles GM installed these on, including engines? At present it's in a 1963 Chevy Impala SS w/327 300. Don't believe it's the original trans.

Answer
Can you send me the VIN number and the cowl tag codes. then I can work backwards to see what the original transmission was. At this point I have checked half a dozen sources an not come up with the numbers that you have given me, so lets work backwards and then I can go into the interchange reference manuals and see what else will fit in place of the original.
Brad