Stalls in Gear, Automatic- Restarts Good- Can Slam it into Gear! EEEK

Pretty sure lock up converters were a 78 and up thing for the Mopar transmissions. Your small block will have the A-904 and unless it was replaced with a later model not likely to be a lockup unit. This being said pulling the transmission is a great opportunity to make some nice upgrades. Shift correction kit, a little more stall in the converter and the low first gear set can really add some fun to that car!