Decoding a833

Anyone with a link or literature on decoding a 4 speed? I'm trying to figure out what a guy is trying to sell me, he wants 350 bucks for a bare 4 speed, no shifter, bell housing etc. if that's a bad deal please let me know. The numbers he sent me are:
PP8333205 0045 (STAMPED)
C 99129H (CAST)
OB334014 (STAMPED)

He said it came out of a 70 or 71 340 demon (I forgot which year he said). Thanks guys!