Intermittent Overheating at Highway Speeds

[Mitch//pa]

Originally Posted by VFRhugh

I installed a 160 deg thermostat and temperature gauge yesterday (from Snyder's). Fired her up and no leaks after idling for about 15 minutes so went for a test ride. It's 94 deg today. The APCO gauge was at 180 when I started down the street. I went about 15 miles round trip with a few stretches to 55 mph(Mitchell OD). Mostly 45 to 50 though. The gauge climbed to 190 and stayed there. I didn't lose any water. Question is, does this seem reasonable? I have searched but not found what normal should be. Does 190 under load sounds reasonable?
Hugh

With a new bergs radiator, a clean engine block, 2 blade fan and a 160 stat my car runs in the 170's on a 90 deg ambient day