Thanks for the response! The output shaft yoke on the new replacement looked sufficiently different from my origianl to scare me off and reuse the old one with a new torque tube yoke and trunion. So the 53 and 54 three spd trannies are the same on light duty trucks. You say there are differences between the "commercial" and the "earlier" trans. Was that earlier passenger three speed or light duty truck? I wonder if the three sped light duty truck and passenger applications were the same. Anyone care to weigh in for me. I appreciate it as I am looking for a new synchronizer gear too.