2000 F350, 7.3 Upgrades for Better Mileage?

I just purchased a 2000 Ford F350, w/a 7.3L, 6SPD 4X4 drivetrain, I want to do some upgrades to help with power and fuel mileage since it will be doing a lot of highway miles. Any ideas on whats best? Thanks:grinyes:

I have a 2000 F250 with the 7.3 and 6 speed and mine was getting about 17/21 and I put a superchips tuner in mine and it immediatly started getting 21/27 and the power is amazing. I am running a 3.73 gear and it you are running a 4.10 gear your fuel mileage will probably never get that good but it will improve it 3-4 mpg but like I say the power is amazing. it will cost you about 400.00 and you can also put a 4" exhaust on and it will help. I cant say about the cold air intake because I havent dont that yet.