Please id this tranny

I have a freshly rebuilt Mopar automatic transmission that I've been trying to id without success. The #s are 8953001836 and 8905 and 5334. There are also some faint numbers that could be 85. There are 3 inch tall raised numbers (by welding?) on the bellhousing: 577-1 . I've been told that the tranny had been rebuilt for racing. Could the 577-1 numbers have been done by the tranny shop?