Going Toyota Land Cruiser Fzj80 axles as ZG said. They can run 35's stock, 4.11's stock gear ratio and the change from 4.11 to 4.56 is the price is like 500$ for both cryo treated gears if I want to swap them, which I will when I'm running 35's. The cruising RPM's will be almost perfectly stock, and I'll be keeping my ABS, hopefully these have the Elockers, that would be the shiz.

 

weight, drag coefficient, driveline loss etc. don't factor in in anyway to ratio... those all effect actual power output as measured at the wheels and efficiency... if you are doing 70mph at 2500rpm into an additional 25 mile an hour headwind, the rpm will be exactly the same (excluding slippage lol) to maintain the speed, however it will require more throttle to maintain the rpm as you would with a 25mpg tailwind...less throttle will be required to maintain the same rpm but its a solid mechanical system for all intents and purposes. Same will be true if you increase the weight, or increase the driveline loss (heavier tires, a/c compressor running, beefier fan clutch, low/****ty oil/trans fluid, other mechincal losses due opening tollerances, wear etc.)