I need opinions

[greasemonkey]

My truck has the stock 4-speed manual and 3.07 rear gears, which is fine for in-town driving, but on freeways from 60-70mph the engine sounds like it is about to explode (I haven't driven it above that). Eventually I will rebuild the engine to a very mild performance, but the truck will still be a daily driver. I have the stock 15" rims on it with 235/75 tires. I would like to put new rims and tires on it as the front tires are getting very worn. Would you guys suggest putting bigger rims on it, like 16/17", to get better mileage with my trans and gears? I intend to drop it maybe 1"/3" or just a small drop nothing radical. I like the Eagle rims, but the ones I like come in 14-16". And the tires I like are Radial T/As. Anyway, what tire/wheel combo would you recommend to someone wanting better mileage and a good-looking tire package? Thanks
John