Chrysler 904 automatic transmission

I have a 1972 Dodge Coronet, I left it lying because the engine broke down, 5 years later I installed a new 318 engine, I turned it on, started, I put reverse, to get it out of where I was, I perform some maneuvers in front of them and 5 min later no longer wanted to enter any change, reverse or drive.
Remove the valve box, clean it, change the filter and oil, but still does not enter the changes, someone who helps me, or that passes me a manual, the transmission is a Chrysler 904.
Greetings and thanks