Cooler pressure being that high is NOT good. That needs to be 100 or under. Anything over 100 is really hard on the thrust bearing in the crank shaft. Cooler pressure that high, is not going to do any cooling when in the cooler because its moving through too fast. Have you been using the same converter through all this? If so, need to try a different converter, or look pump/input shaft/ or valvebody really close. The transmissions i build for 5.50-6.30 cars normally dont make 60-70 psi on the cooler.