1. where is the temp sending unit on a 85 22re? I thought is was on the top of the thermostate housing?

2. would timing not being set right and no knock sensor cause over heating issues?

3. are 22res prone to air in the cooling system?

I have a new radiator,water pump and thermostate on my rebuilt motor and it was over heating at idle so i changed the rad and there was no thermostate in it so added one now it runs great around town but on the interstate it over heats guage goes right to max but when i slow down guage drops, poor thing just hates to go 70 when I pulled over truck really was not running that hot, water was not boiling over and man i had the guage maxed. but when i got home the water level was down. so i was thinking air pocket or maybe me not having a knock sensor and the timing set by ear might have contributed to this over heating. anyone have seen this befor???
-Rob
-Floral City
-Florida