Get a spare oil pressure sending unit and put it in a compartment.  Have it on good authority that GM had quality control issues with those units across all the engine lines in the late 1980s and into the 1990s.  While on a trek across the northern plains states had the oil pressure on "The Beast" drop to ZERO when miles from anywhere.  Turned out the oil pressure sending unit had failed but it caused a bit of momentary heart failure when the gauge dropped to nothing while running at 80mph.

I found some dry rot on my tires and replaced them immediately. Treads looked good until you looked close!!