After working in a dealer shop for 25 years, I can say that just about every fuel pump in the tank I had to do, had darn near a full tank. The book usually paid roughly 4 hrs for the job (drain tank, drop tank, ect ). I never dropped one tank. I would unbolt the 4 bed bolts, unplug the light harness and tilt the bed up like a dump truck. This allowed plenty of room to get to unit. Swapped them out, dropped the bed, BAM !! Paid 4hrs in 45 minutes. Gravy Train...