I'm a long ways off from needing something like this, but maybe you can answer some questions for me. I've got a '79 K30 with dual tanks (older style switch and valve) that I would like to run dual TBI units on. I want to keep the original dash switch if possible. My only idea was to run a frame mounted pump, ahead of the selector valve... which I don't think the pump would like. Is there something that could be done, so I could run in-tank pumps and keep everything else appearing as original?
Aside from what
@gmachinz said which would work perfectly, I don’t believe a good external pump just ahead of the tank valve would be a problem at all. Most pumps are as you know designed to push fuel and if you get it lower than the bottom of the tanks it effectively is. However there are a ton of in line pumps in use and not all are actually low enough to create a siphon. However length of line before the pump, number of bends, restrictions and elevation all matter and minimizing the magnitude of minor losses makes a difference.
My example is adjectival but the carbureted 86 has a Vortec 454 with no fuel pump provision.
It was originally running off a little universal fuel pump mounted near the original engine mechanical pump, wired directly to the choke wire for power iirc. It worked but smoked the pump every time after a few tanks of gas…side story, told me it was never really driven hardly at all after the last 454 swap (which the 3 owners ago owner verified when I found him a year later). It had a sketchy power source and was pulling through over 10’ of fuel line. And no fuel pump shutoff unless the key was off! Lol
After painting it I planned to put a real pump back by the tank switching valve. So I ran good fused power to and from an efi relay back to the pump location. I slapped the newish cheap Edelbrock universal pump in “temporarily” back by the tank valve until I got everything else done.
“Temporary” was over 4 years ago now. The truck doesn’t get driven a lot but in the last 5 years I’d guess it’s gone through guessing 40-50 tanks of fuel on that same little cheesy pump and still works great. Sounds the same, no symptoms of fuel starvation or the pump crapping out.
Based on that I’d surmise that a quality inline pump would basically last forever. Since the mini pump has held up well enough that it has fell off the to do list.
