Welcome captain. Here's some info:
Wiring diagrams:
http://67-72chevytrucks.com/vboard/s...d.php?t=738404
Idiot light to gauge conversion threads:
http://67-72chevytrucks.com/vboard/s...d.php?t=295681 (this one is very helpful)
http://67-72chevytrucks.com/vboard/s...d.php?t=645940
http://67-72chevytrucks.com/vboard/s...d.php?t=598240
http://67-72chevytrucks.com/vboard/s...d.php?t=592617
If you notice the little "Google" box in the upper right part of your screen, you can find much of what you're looking for with a quick keyword search. Make sure to click the "67-72chevytrucks.com" radio button before you click the "Google" button so your search results only come from the site rather than the whole interweb.