Ran badly when handed down to me - 3-4 mpg, no power. Rebuilt the carburetor, and that was almost like putting a new engine in - much more power, mileage up to 12-13 MPG.
Rebuilt entire brake system (master cylinder, power brake booster, front calipers + rotors, rear pistons + drums) as most of the parts were either leaking or just worn out.
Had to replace the solenoid that switched between the dual gas tanks once.
Had a tendency to run hot in the summer (temp guage would sit at about 3/4) - had original radiator, though.
Steering was extremely loose, but controllable.
Had an appetite for starters - every 6 months I'd have to replace it.
Ford's (in) famous DuraSpark II ignition system - had to replace the control module every 6 months as well (new ones were only $15, always carry a spare if you own a car with this system).
Heater core ruptured around 280k?
Transmission finally went out around 300k.
Engine always leaked LOTS of oil from the rear main seal - running straight 60 weight oil would usually lose a quart every day. 10W30 would empty the oil pan within 30 minutes.