I've seen lots of post about changing the thermostat, which is a pain to get to. I'll show you an easy way to do this without fighting the exhaust crossover removal and lower housing bolt.. Time=about 1-1.5 hrs. You might get a new TB gasket first. Got mine at O'Rileys for under $2.00 part # 61503 and it's a fel-Pro..
pic1=A pic of the part no and gasket for throttle body
Pic2=you need to disconnect wiring to areas in red. There are a few other things attached to throttle body on top and the cables to throttle and trans.
pic3=Shows the heating hoses attached to unit
pic4=Shows the location of bottom bolt which also holds the bypass tube in place. Also the throttle body heat disconnected.
pic5=View of thermostat housing with throttle body removed
pic6=Shows access to lower housing 13mm bolt. I put a rag under housing as shown in next pic first to catch bolt in case you drop it.
pic7=Here you see the rag in place.
pic8=After loosening you can get to it with fingers.
pic9=Exposing the thermostat (already removed) and where it goes..