I would start with a complete and thourough tune up. Cap, rotors, plugs, wires and air cleaner and check/set the timing.
I would replace all the rubber hose that is underhood to eliminate any leak problem that could be caused by brittle hose.
Then troubleshoot the engine with new components.
Drain the coolant system and flush the radiator and install new.
Drain the engine oil and change the filter.
Drain the tranny fluid and change the filter
Drain the rear diff fluid and replace the gasket and add new fluids
Inspect the brakes and if the aren't new replace everything: rotors, pads, bearings drums, shoes and hardware and the rubber hoses. I would also flush the brake fluid out also.
Inspect the front suspension bushing and replace/rebuild if needed and have it aligned.
Something like that?
Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project