Go borrow a hand heald (Lazer) thremometer and make sure it really is running hot. You can also check the radiator for hot spots or cold spots.
100% water is the most efficient coolant. Try it with some of the aftermarket "water wetter" additive.
Running hot at idle, which has no load on the engine, could mean your timing is off, radiator is not working, water pump is not working, or the fans are not working. Check the tune up first, then move to the radiator. Higher rpms of driving helps push water through a bad radiator, at idle there is not enough pressure to move it.
New water pump should be OK, and you can see and hear if the fans are doing there job.
Mine runs hot at the front of the head where the sensor is. At the back of the head and at the radiator, is 10* cooler. Just something about the design I guess.
Keep is posted on what you find, Joe.
