You may be able to modify the truck fuel sender to work in the Elco tank. The depth of the tank may be different. Or, find a repro Elco sender on EBay, OPGI, etc. for an 87-88 TBI motor. The tanks fron those years will al;so have the baffles to keep the fuel from uncovering the pickup during turns and stops when the fuel level is low. As Turna started to say, if you don't need emissions, you can use the 5/16" charcoal vapor return line from the tank as your fuel return line, just flowing the other way.
