Heck, stop with the little things... if you want to lighten it up to go faster, let's get serious:
Yank the bed. If you're not going to tow with it, you probably won't haul anything, either. Lose it. (This will make mounting a 5th wheel hitch easier, and no tall bed sides to worry about, either).
Lose the 35 gallon fuel tank - replace it with a 5 gallon fuel cell. Should be real easy to do when the bed's off.
That rear window? Doesn't do a thing for ya... . toss it. Replace it with a window net for that ultra-cool look. The same goes for the four side windows.
Heck, while you're at it, lose the rear doors. Again - they do nothing for speed. Just more dead weight looking to come out.
Yank the transfer case. That's about 120lbs. of steel and aluminum that does nothing for the go-fast-ness you're after. Get a 2WD transmission tailshaft and a 2WD rear driveshaft. If you're really serious, lose the whole front axle and replace it with a 2WD spindle setup. Remember- lighter = faster.
Pull the whole damn A/C system - compressor, condensor, the works. That's weight, AND drag on the engine. Your truck is cool enough by itself that it should be 20° below ambient all the time, anyway.
Gut the interior. Carpeting, center consoles, upholstered seats... it's all ET-sucking weight. Take the floor down to bare metal (use a REALLY thin rubber mat, if you MUST), and put in an aluminum (or better yet, carbon fiber) racing seat. You'll have to weld a crossbar behind the seat to attach the 5-point harness. Unfortunately, this will add some weight back, but hey, ya GOTTA have some restraints when this thing hits 200MPH.
There's a whole lot more you can do, but this should be a decent start. Good luck
-Tom
Attention: TDR Forum Junkies 
I'm just messin with ya like everybody else here is, bottom line is it's your truck do what YOU want and have fun doin it!!!!!!!!Oo. Oo. Oo.
