Stopped after 3 hours driving 60 mph at 90° and the overflow puked out some coolant. I ran the overflow above the MAX mark to help bleed the air out of it when I bypassed the heater core.
Checked it later and it had settled in at the MAX mark. Boy those Mopar engineers were smart 41 years ago.
Factory thermostat is an oddball 180° high flow unit. Fan is a solid 8 blade with a thermal clutch. The clutch locks up, but I wonder if it isn't a bit lazy. Unsure as to how a 220° set point thermal clutch is supposed to keep a motor at 180°. New clutch is cheaper than a rad so I'll try that first. Not so sure about tranny temperature though.
