I tow 10k lbs trailer in western mountains. Have 04.5, 6 spd manual, 64/80 superphat, 90 hp injectors, technicooler, monster ram, fass fuel, numbers we ran last were: LT-15 HT-25,LR-10 HR-25, LD-12 HD-18....ran high egts with uphill 1400+ until down shifting, and sucked fuel, 6-8 mpg. Wanting suggestions for improvement????