Your best option might be to move out of the left lane,over to the right lane and slow down. Gotta love them 3.92's at high speeds,lol. If you're outdoor temp is 108F,you might want to stick a 180 thermostat in it for the summer temps,then swap your original 203 thermostat back in for the cooler months.For all it takes to swap t-stats on the trucks,it's an option to consider,along with slowing down,or replacing your 3.92's with 3.21's. The differance in rpm between 3.21's and 3.92's at 90 mph would be like slowing down to 74 mph. The same rpm you turn at 90 mph with 3.92's would put you at 110 mph with 3.21's