there may have been some minor changes from the OBD-I to the OBD-II model years, but yes, in the same year, a 5.9 out of a Dakota R/T is the same exact motor as a 4x4 Jeep as a 3500 Ram pick-up.

same block, crank, rods, pistons, cam, intake, heads, etc. you will see that some vehicles have higher Hp ratings, but that's because of muffler changes, such as on the Dakota R/T that was listed at 5 hp more than other equivilent vehicles.

the stock long block is good for about 400 crank hp with just a cam, intake, and exhaust change.