after struggling to get through I-80 last weekend i have decided to do a gear change on my truck. my goal is to get over 75mph on the highways or at least get the truck into 5th gear. currently i could get up to 80+ but i would be revving it to 4k rpm in 4th gear. i know the truck can take it, but i would like to preserve some fuel economy, even if it is 7mpg compared to 5mpg.
the truck is a 2001 f250 v10, manual 5sp, 3.73 gearing, stock tire size (265) with 112k miles. i was thinking 4.10 but don't know if it is enough or 4.30 but don't know if it will be too low to get around town. currently the truck is used for towing a 5-6000lb trailer and as a back up vehicle for the race van or a snow vehicle.
any thoughts?
any other mods that would make a significant difference other than buying a diesel?