It could also be a 250 or 200 I believe. If it has a lockup converter (if it's from the mid '80s it most likely will) it will have a square 4-prong plug like a 700R4/2004R. You can use either in a non-computer-controlled car, but to get the lockup you will need to wire the circuit for it (not very complicated).
http://en.wikipedia.org/wiki/Turbo-Hydramatic#THM350
http://www.oldspower.com/vb/showthread.php?t=839