If my memory is correct, those trucks had the shut-off valve as original equipment. I don't remember when they were no longer used, probably when gas tanks were moved from behind the seat. But even with those valves, normal shop practice when changing a fuel pump was to cap the line and not bother with the shut-off valve. You lost a few ounces of fuel that way, but if you were quick with your wrenches, your finger and capping the line, it was barely a couple of ounces lost. And you didn't have to remember to turn on the valve when finished.
Harvester
