Pull the fill nozzle (three screws and two hase clamps) and braze two connections(I used 1/4" npt pipe couplings) onto the vent line. You will want the fuel to go into the lower conn. and tie the top conn. back into the top of your aux. tank. If you come out of the bottom of your aux. tank, you can get by without a pump. If you come out of the top(which I prefer) then you will need a pump. I am using a Stewart Warner pump that was designed to pump diesel for a fork truck. I pump my fuel through a 10 micron filter going into the main tank to save my Cummins filter. I run from tank to filter then to pump then to shut off valve, reason being that I filter the fuel before it goes to the pump or filter. I used 3/8" automotive fuel line for the plumbing. I am using a timer type manual switch(the kind you use in a bathroom to turn off the sunlamp) so if I forget to turn it off it goes off in a maximum of 30 minutes, with the vent line, if the main tank fills, it just pumps fuel back up the vent to the aux. tank. I got my 12v elect. valve at NAPA. bg