That is helpful. I looked into the Competition Engineering sump (likely the one at Summit). They instruct to drill 5 2.5" holes allowing the fuel to drop. I've wondered if smaller holes would allow better retention of fuel in the sump. The sump is 3" deep at the rear, and spans 11" x 7" or so. I would think this is a large enough area to create a 'pool' in the bottom of the tank to keep the pickup covered most of the time. With 3" sides near the back, I would think it would hold enough for most situations on the street.
This sounds similar to what you'll be doing. I'd probably keep 1/4 tank of fuel in as much as possible, again, this is a street only car.
I would then turn my old pick-up into the return, and install a vent somehow.
This, of course, is if I pony up and buy the EFI in the first place
