Post #18 has the diagram.
http://67-72chevytrucks.com/vboard/s...d.php?t=511477
You will need both brake switch inputs hooked up, one to the PCM and one to the TAC. What kind of cruise switch are you using? If you're using the factory one that came in your '82, then you will need to change out the switch inside of it to a 4 wire switch. The thread that mongo linked has some pics on how to do that on page 2.