The pan and modulator, on my TH350C look just like the ones on my TH350 in the coupe AFAIK. I doubt the truck was available with a regular TH350, but one could have been transplanted.
The plug is on the driver's side, I think. It is square, and I believe it faces upward. It might not be obvious if you have not seen one before. It looks like this one on a 700R4.
http://www.iotech.no/corvette/techni...kup_socket.jpg
Slonaker