[Steeveedee]

There are service and repair manuals. Do you have them for your truck? If not, click on the link and download it and the wiring diagrams. You can compare them against the AAW harness. A quick check would be to see if the wire out of the stop light switch to the turn signal switch is white, like factory (or that could have been changed in the intervening decades).

https://67-72chevytrucks.com/vboard/...ghlight=hatzie