Classic/Antique Car Repair: 68 300THM TRANSMISSION, vacuum modulator, auto body shop

Question
MY 68 TEMPEST HAS A 300THM TRAS.yoU CAN HEAR THE TRANNY SHIFT INTO GEARS BUT IT WON'T DRIVE. DURING MY INVESTIGATION I FOUND A LINE THAT WAS NOT CONNECTED TO THE TRAS.? THIS LINE STARTS @ THE CARB(2BL) RUNS PASS THE TRA COOLING LINES OVER THE TRA MOUNT & STOPS A LITTLE PAST WHERE THE COOLING LINES HOOK UP(PASS SIDE OF TRA). I KNOW THERE IS A VACCUUM MODULE THAT IS ATTATCHED TO THE TRANNY. I UNDERSTAND IT ALLOWS THE CAR TO MOVE IN GEAR. SO MY QUESTION TO YOU IS WHERE IS THIS MODULE MOUNTED? HOW IS IT MOUNTED? WHAT DOES IT LOOK LIKE? AND DOES THIS SOUND LIKE MY PROBLEM? I BOUGHT THE CAR FROM A FRIEND(THIS WAS HIS ONLY RIDE) HE HAD A ACCDNT. IT SAT AT A AUTO BODY SHOP  FOR 9MON. SO IF THAT PART EXISTED ON THE TRA,MNT & ALL, MAYBE SOMEONE "BARROWED" IT. I TRIED RESEARCHING IT BUT IM NOT EVEN SURE THATS THE CORRECT NAME! PLEASE HELP! SIGNED FRUSTRATED!

Answer
The vacuum modulator controls the quality and timing of the shift, but it wouldn't cause your symptom.   If your driveshaft is present and hooked up, the problem must be internal to the transmission, probably the pump, front clutch, or roller clutch, but it really doesn't matter because you are going to have to take the car to a pro to find the problem anyway.   Call a tow truck!

Sorry.

Dick.