Here's a stickied thread that should answer any questions.
http://67-72chevytrucks.com/vboard/s...ad.php?t=13698
It's fairly straightforward.... remove the old dizzy, drop in the HEI, run a new 12 ga. power wire, replace plug wires with 8mm wires, and re-gap the plugs from .035" to .045". Of course if the plugs are worn, get new ones, same type as stock.