Removed the in cab tank and put a 15 gallon tank under the bed. I have a Holley in tank fuel pump. Ran steel lines from the tank to the engine compartment and incorporated a 10 micron filter in the pressure line. The tank is vented with a roll over valve.
Added a Fuel Link to get the 73-10 ohm tank sender to work with the fuel gauge. That still needs some fine tuning.
As long as you don’t mind having the tank in the cab, it would be a lot cheaper and easier to use the in cab tank. You could use an external pump and utilize the tank drain for a return.
Dan
35 CC Case 38 Chevy Pickup 51 3100 AD 58 3100 Apache Fleetside