Here is a pic from the '70 Plymouth FSM that applies to Challengers and both auto & manual trans that shows the two bolts securing the trans to the trans mount and the placement of the spacers between the trans mount and the mounting bolt's captive washers.

The nuts mentioned above as far as the E body trans mounting, were two threaded studs inserted into the bottom of trans ext housing and two nuts w/captive washers used as well & using the same torque specs?