Concerns? True chassis cab trucks have unique frames once you get to the kick-up behind the cab, so besides the wheelbase difference (although depending on year and model some chassis cabs were available in "normal" pickup-style wheelbases) the frame profile is entirely different. They tend to be ladder straight and on 34" centers, unlike pickup frames which taper a little from front to rear.
Besides altering the wheelbase you'll also need to fab up your own mounts for the bed.
I know you're talking about a SRW 2500 but just FYI in the case of DUALLY chassis cabs, you'll find the rear axle is 8" narrower than a regular dually pickup axle, so that brings another twist to the conversion.