the TH-400 has three ribs at the rear of the main housing ( L and C ) while the short tail shaft housing has NO ribs ( L ) and the long tail shaft housing ( C ) has TWO. the TH-350 ( R ) has a single rib at the rear of the main housing and NONE on the tail shaft. sorry i don't have any other trans for comparison. To me it looks most like the one on the right in the first pic in that post do NOT worry about the bell housing shape. that has nothing to do with what transmission you have, it only tells you whether or not the trans is supposed to be used with a chevrolet engine or a BOPC engine.
