Excellent thread!!!!!!!!!!!!! Now, lets see.... I was gonna put "tune-up" on top of the list, but I think we should keep maintenance and repairs out, unless the repair is a work-around to use X instead of Y to save some bucks kinda thing. Anywho...
1: LEDs in the dash, dome and cargo lights. Brighten up your life for under $50 and a few hours of time. Do this now and thank me later. Lots of good info on how to do this here.
2: Newer radio upgrade. I hate aftermarket radios and wanted some better sounds. $25 for the adapter plug, a free radio swiped from a friend, and an hour or so and I was rocking out. These radios can be had for $10 on craigslist. Not sure what the junkyards get for them. Replacementradios.com sell the plug, or you can go real low budget and hack up your factory wiring, if it hasn't been already. Chopping wires maybe the only option for guys with older trucks. And if you scoop up a radio that had a slave (single in dash, or remote changer) CD player, replacementradios.com sells a doodleybob that you plug into the radio that you plug your iPod into and then you can CONTROL the iPod through the radio.
http://67-72chevytrucks.com/vboard/s...d.php?t=522852
3: Buy some SEM interior paint and go nuts. Do it in sections and keep your costs down. I'm $50ish into doing my crew cab and prolly need 2-3 more cans to do the three door panels I have left.
4: Redo that sagging headliner. New material and glue cost me under 50 bucks.
5: polish your plastic lenses. Lost of headlight resto kits out there on the cheap, and they work on taillight and turn signal lenses, too. I've used Duragloss and Mothers Mag and Aluminum polish on a rag rubbed in by hand with great success.
I'm sure I'll come up with some more ideas or remember **** I've done on the cheap.