I have the 318, but an '89 model which has a roller cam which gives 10 more HP(185) and some more torque too.
My transmission is an A-500 or 42 RH which is based upon the 904, which is the smaller version of the venerable 727 weighing 100Lbs less.
I recently had electrical issues preventing me from using overdrive and the lock up torque converter, and 3000 rpm at 65MPH is annoyingly loud, where as in OD Lockup it is about 1975 rpm.
The 727 with an overdrive unit tacked onto the end is called an A 518
or 46 RE or 46 RH and there is lots of information inline about converting to them from a base 727.
