The truck is a brick. The trailer is a brick. Slow down, take your time, set the cruise at 68mph. No its not "cool" but you will beat your truck up less. Even when I owned a diesel and towed heavy, higher speed will always kill your mpg. Its like there is a wall after 65-70mph. RT

 

I had a 91 5.0 Sierra and anything over 70 was a struggle until a built the engine up. My advice would be to tune it (TBIchips.com), throw an intake on it and a lower temp stat. If it is a 4.3, get a 5.7.

 

Vortec heads on the older V8s do WONDERS!!!