Need some pointers on what to do. Driving around in the city my transmission will hit 350+. In the mountains it will get so hot that the guage will not even function anymore. Needs some hints into what to look for? Bacically i have a 1989 k5, 350 bored .30 motor, 4.56 gearing and 36 inch tires. my transmission does have a aftermarket cooler on it.