Straight from Dodgeram.org:
The NV241D is a heavier duty Dodge version of the 241, with a larger input shaft and larger bearings to withstand the torque of the V10 and diesel engines.
The NV241HD, an option on Ram 2500's and standard on Ram 3500's built after 1998, has a stronger case and wider drive chain to better withstand the shock of snow plow service, a PTO cover and drive gear, and an extra bearing to support the thrust to the main shaft created by a PTO adapter.
Except for dimensional differences and the PTO port on the NV241HD, all of the cases are almost identical in appearance. An identification tag is attached to the rear case of every transfer case. The tag provides the transfer case model number, assembly number, serial number, and low range ratio. The transfer case serial number also provides the date of build. For example, a serial number of 9-10-93 would represent September 10, 1993.
So you unless you have the optional NV241HD, looks like you have the NV241D. You'll have to crawl under the truck and check the tag.