84 300TDT cooling system questions

[JDmills]

This spring, I noticed that the car would heat up when pulling a hill. the tempature gage would go to 95 or so, and then drop quickly once the downhill portion of the drive showed up. actually that has been consistant since owning the car... as it will do the same when pulling a longer hill, (speed is higher, so it takes longer to heat up) wait, is this a case of a bad engine fan? in that it seems to heat up the most when traveling at moderate speeds. At fifty or so it will heat up but much more slowly, and cools down once the power demand is reduced. but at 35 mph it just runs kinda warm, not hot not cool but in the middle.

I Just replaced the thermostat, and radiator yesterday, and discovered that the car runs hotter than before... The radiator does get hot, so there seems to be coolant going through it, and the thermostat now appears to work, as it opens and presureizes the system at 80' So I guess the next question is how to test the fan clutch... off to do a search. But if there is some thing obvious that i am missing please jump in.
Jason