Hey Doug,
Did find and install an upper radiator hose spring, a 170 T-stat (same as Gen III), drained some of the OE fill and replaced it with distilled water and 2 bottles of Redline's water wetter.
At the track a week and a half ago, coolant temps at peak were just over 200 F. Track was relatively short and twisty but air temps were only about 80 F during the heat of the day. Car cooled down immediately after I stopped pressing on it.
It seemed to run quite a bit cooler than the last time at the track.
Dan