Diesel Bombers - 95 dt466 with p7100 pump

Hi I'm Andrew. I installed my 66 dodge crewcab powerwagon body on my 95 international 4700 chassis with a mechanical dt466 and a spicer 5 speed. I dont have a pre turbo pyro yet, but my post turbo temps hit 900 deg way to fast with a load (say 5000 on trailer and my truck weighs 10000) on my truck. I have plenty of fuel but have to back off because of temps. the only "mods" done sofar is fuel plate full foward and AFC maxed. I would like to add a 13 speed in the future because droping a gear really slows me down. My truck has 3.54 gears. Would a charge air temp gauge be helpful? I need to hookup my new boost gauge. Any info would be great because im picking up a 36' goose neck trailer and really want to beable to pull a few tractors at a time.
Andrew