Yes, what you got is a W56-C, a 1989-1995 W56 that uses a late-model forward-shift style t/case, most likely a
Type 6-A.
The difference between a W56-A and a W56-B is that the center support plate on the 'A' is Aluminum while the 'B' is cast iron. Also the reverse idler gear on the 'B' has a more narrow foot.
BigMike