To begin with I have heard that swapping to manual hubs on the front end will help with gas mileage. Is there any truth to this and is it even possible on a 2002 with independent front suspension, since is have heard some say it can be done and some say it can't?

Also I would like to add 2 inch lift blocks to the rear axle to give the truck a better stance but don't want the front end to sit low. Would new torsion keys or spring spacers be the best route to go? I would like to maintain at least a some ride quality and i have heard that new keys make for a rough ride so I'm just wanting some opinions. Also please post links for affordable spacers/keys if you have any.