i beleive they are the same. osmeone correct me if im wrong but.. all the frames were the same from gen to get. meaning 88-98 2wd frames were all the same. 88-98 4wd frames were all the same.
to be 100% sure i would take measurments of the bed underneath. i would measure mount to mount. cab to bumper. width. and if they line up then you are good.
ive heard/not seen a few guys say there trucks used to be singles then they make them duallys. but they could have just done replacement fenders dually's and added them to there trucks and added the dually kit fo the rear.
i say go for it man. then post pictures of everything you do so we all learn something.