Welcome to the forum.
Lets start with the electric section of the forum (see post 12) -
http://67-72chevytrucks.com/vboard/s...d.php?t=378484
In the FAQ section there are links to wiring diagrams -
http://67-72chevytrucks.com/vboard/s...d.php?t=646002 - "See Electrical Threads:"
Such as this one for instance -
http://www.6066chevytrucks.com/id17.html