I haven't bought a Humvee yet. I think they come with 4:56 gears. Is it possible to replace them with 4:30, 4:10 etc gears? Is the truck so heavy that it really needs 4:56? I plan to use it as a work truck nut a mud bogger. It seems a gear swap would be a big improvement. I know there is also an over drive trans available. Perhaps that's the best option. Not sure of price on either of them.