Valve bodies w/PTKD interchange ?

Most but not all valve bodies will interchange between 904's and 727's. Some trans are lockup and some aren't and they don't interchange. You can also run into the issue of one mounting bolt not lining up when switching between 904's and 727's. I thought all 64's were cable operated? If your just looking to add PTKD why don't you just order a PTKD add on kit from A&A so you don't have to swap the VB?
You are correct about 64's having an internal cable for gear selection..except for trucks. The trucks had shifter on the dash. A cable was used from the shifter -to the tranny_ on top of the tranny were the more modern two lever arms (one for gear selection/ one for kick down..like most 67&up mopars use) So the truck were the first not to have internal gear selection cables.
And from what I've found out the early VB's do not have the correct porting for the PTKD kit. But I will check with A&A.