Are 96 through 98 Dodge Ram 1500 transmissions.

Should be the same but the internal gear ratios might be different. The guys at salvage yards use "Hollander Guides" that list all parts and which applications they fit. If both applications are given the same thee or four-digit code number, they should be the same. You can also ask at the Chrysler dealer's parts department. If both applications call for ordering the same part number, they're the same. There could be some differences on the outside and you're expected to transfer things from the old one to the new one. The guys at the dealership I used to work for were happy to look that stuff up because they knew if they made you happy you could become a future customer. The people at some dealerships don't want to bother with that because they're too busy with other stuff or they're too short-sided to see the benefit in helping you out. They should not be a reflection on the entire dealership.