Thanks guys, looks like a gravity feed from the tank would work if the tank was full, but not at 1/2 full. Think I'll get a buddy of mine to fabricate a little (4oz?) tank with 2 lines on the bottom, one on the top. Returns from the injectors and pump to the bottom, feed to the thermostart at the bottom, return to the tank at the top.
I knew the fuel pressure varied with throttle position, just picked 200 pounds as a maximum. I remember that a truck I once had was set at 180 lbs. This pump is a littel different than the truck pump, throttle shaft is off the back side of the pump, not the middle. Load governed as opposed to speed?
Also like the picture of an 8.3 with two. We have one at work (92 model grader) but starting is never an issue because it's parked in a heated shop. Had problems with coolant in the oil lately, after changing the head (gasket leak) and still finding coolant in the oil, thay elected to exchange the whole engine. New engine doesn't have the same grunt, but burns less fuel in a day. Hoping it will get better with some hours! Okay for grading, severely lacking pushing snow.