take a look at the vent hose nipple on the top of the tank which sits in a recesion. poor design. water can acumulate on the tank and settle in the indentation letting water intrude into the vent nipple contaminating the fuel in the tank.
chrysler has been known to void warranties on fuel systems where water was present in the fuel. go figure. their stupid design is the reason there is a water intrusion problem.
the solution is to place a hose over the nipple and run down the side of the tank a bit. memory tells me 5/16th. this should only be on the lwb trucks as to my memory the swb do not have the indentation. this is on 3rd gens.