How to replace the fuel sending unit on a 1987 Toyota Pickup?
First jack up the truck and remove the rear whee, then disconnect the fuel hose and breather hose to the tank. Then loosen the metal bands holding the fuel tank in place. The unscrew the five nuts holding the sending and gauging unit in place, after disengaging the wiring to it. Replace the unit, connect the wires, fasten the nuts, fasten the fuel tank metal bands, then fasten the hoses, make sure there are no leaks.
A good option would be to go to your local auto parts store where you can ask someone behind the counter, or search the shelves where clips plugs and caps are found, however to find an exact match to your radiator you should go with one provided by the manufacturer of the radiator or a similar product made by the manufacturer.