I just had my 700R4 rebuilt and beefed up which costed 1800 bucks!!!!! Everyone says heat is what kills this tranny. The Trans shop told me I had 3.07 in my rear and I had to change them if i wanted the trans to last. Before i changed the gears I installed a trans temp gauge to see what the temp was. When I drove around town it would hit 210 no problem.(I have the sending unit for the gauge in the line going to the trans cooler) I had the gears changed to 4.56 and the temp stays between 175 to 185 in town. For the first time i took it out on the highway and she hit 210 again. I do not like this. Any one have a idea why it gets so hot on the highway. Also does anyone else have this problem. I Do Not want to spend that kind of cash again. 1986 K5,Np-208,35 BFG,300 Horses under the hood.