the FSM, the book from monroe, plus a book from the ATSG [Automatic Transmission Service Group] will be all you need to rebuild a 727.
add a master rebuild kit, and any upgrade parts you desire, [servos, bands, etc.] and dive in.
those are the easiest of the automatic transmissions to rebuild.
but remember, "Cleanliness is next to Godliness" ! if you think it's clean, clean it at least two more times !