Well I picked up and installed my stant # 13928 thermostat and as it turns out it comes in three pieces . A regular sized 180 deg as used in a 235 , a brass adapter that mounts into the base housing to accept the thermostat and a rubber like spacer that fits between the top of the thermostat and the and the top housing which I guess is to keep the thermostat from popping out of place when the coolant is flowing .
The thermostat does not fit wholly into the brass adapter when closed allowing coolant to bypass a bit while warming up .
I had to open up the hole on the top housing to allow for the brass adapter , but the motor now runs closer to the 180 mark .
I haven't tried the heater yet but I suspect it should perform better now with the engine running warmer .
John
