Very little actually. Routine maintenance mostly.
Rebuilt the carburetor every few years. With a Holly 4 barrel, that's routine anyway!
Over the years, I replaced: starter, alternator, water pump, wiper motor, window motor, tie rods.
Nothing was done TWICE and I credit that to using ONLY factory parts, no aftermarket.
Rear main seal replaced 2001.
Great truck.
Comfortable ride & seating.
Plenty of power, even after all these years.
Fuel mileage was atrocious. of course, but that goes with the territory!
Honestly can't think of one BAD thing to say. I suppose that says a lot in itself...
I am the owner of the 1982 F-150 XLT with many parts replaced at least twice, but keep in mind, it looks and runs like new and has nearly 400,000 miles on it now. No oil spots on my driveway thanks to two gasket changes over the years :-)