No, they are the same and yours should work on his truck, Johnny06.
The difference is whether it's for hydro-assist or not.
His late 1997 truck should have hydro-assist, since '96 was the last year for vacuum-assisted brakes on a Cummins equipped Dodge truck.
A hydro-assisted pump has TWO return fittings on the reservoir can, plus the pump itself is a higher output in fluid volume.
When Dodge jumped up to hydro assist, the whole assembly changed, so you can't even swap a hydro-assist P/S pump onto a non-hydro truck, because the adapters between the 2 vacuum pumps and the power steering pumps are different.
Mark.