Transmission service - Teach an old dawg new tricks!

My questions are:
  • About how much fluid should I expect to drain off?
  • What is the appropriate trans fluid to go back with? Don't need anything fancy, just what is adequate back in the day that is equivalent to that now.
  • On the Oddity, I connected a clear hose to the dipstick tube and hose clamped it (just tight enough not to leak) and refilled the trans that way. Is that the way to fill the trans on the 727?
Answer to question 1: About 1 gallon maybe a little more
Answer to question 2: Mopar Part number 68218057AB (ATF +4) fluid
Answer to question 3: I just use a funnel and put the fluid in through the dipstick tube