Trying to identify. A transmission

the parts guys are just jerking you around. look at the pan, I believe a 904 is a simple rectangular shape. the 727 is only somewhat rectangular and it has a bulge on the left front of the pan. If you Google transfer pan shapes, you'll see what I mean. Im no transmission guy, but I can't believe there is much difference in rear seal, once you've identified whether it's a 727 or 904, as long as the trans is a slip yoke.