If the truck has fairly high miles on it, I would suggest an "excellent idea", is to replace the fuel pump in the tank at the time of changing out the fuel sender. I just know from having replaced the sender myself a couple of times, in the area I live we have corrosive products poured on the roads during the winter and without fail the fittings at the sender unit won't swivel on the outlet tubes and it twists the tubes right off in the process of removal even if it was just to drop the fuel tank for other reasons. You may have a totally rust free unit and not have those sorts of issues. If you did decide to change the fuel pump then, make sure you install a quality one as the last thing you need is to swap out a Delco unit for some off beat Chinese garbage pump that will let you down !.
Of course everything that could be seized was when I did drop the tank, from the tank strap bolts twisting off and having to get new straps to rivet on to the brackets, to the threaded insert in the box cross member breaking up its holder and spinning up inside because of the bolt seized to that internal nut.
Change the frame filter and should be good on that end of the fuel system.
Others may have different idea's on this but I would hesitate to install an open style element that sucks in hot air from the engine compartment/heat rejection from the rad and towing would make it even worse. Bringing in air from the factory fender system or grill ( I'm not sure how that year was set up ) is better simply because of a cooler air charge but if its restrictive ... I don't have the answer there.
Unless you see different, most likely a spark plug, wire, dist cap and rotor change are in order, or at least anything that appears suspect at all, basic tune up parts although I realize you would already be on the ball in having those items on your list.