transmission interchangability ??s

These are not directly interchangable. The problem is that the park mechanism for the 65 and earlier cable operated trans is in the tailshaft, so changing to a later style tailshaft will yield you no park. I had a big block push button trans from a 64 Newport and found a 65 trans from a small block car in the junkyard which had the slip yoke and cable operation, so my trans guy simply switched the 2 tailshafts and voila!! slip joint yoke on a big block pushbutton trans. You will need to find a 65 trans with the slip yoke and push button operation to use, which at first I thought all 65 transmissions had, but apparently it was a mid-year switch. Good luck finding what you need, I know they are out there but they are elusive. Geof