Recently purchased a 96 f150 4.9 liter. 155,000 miles. Truck runsgood but maint. history is unknown. I have completed or am in the process of the following: Oil and filter change Manual 5 speed fluid change maxlife syn. ATF Rear end 85/90 and limited slip additive change Antifreeze drain/refill (scared of flush, OLD antifreeze and grime) New radiator cap New thermostat/gasket Front brake pads rear brake shoes New pcv Motorcraft plugs, cap & rotor and wires Air filter New fuel pump (sending unit was bad) Fuel neck (original was punctured/leaking) Fuel filter 4 new monroe shocks New drive belt Refurbished: Ac compressor/drier/oraface tube, flushed and recharged system. Windshield washer pump replaced Door hinge repair kits for sagging doors New side mirrors for mismatched mirrors Anyway i need a salvaged bench seat, but other than the above what would aid reliability\longevity?