I still have the factory wiring harness with a brown (unattached) going to the distributor area. Would this be an indication that my car originally had a factory tach or did GM use generic wiring harnesses that fit more options then perhaps a given car came with.
Krister Meister '66 SS #'s
I don't know about a 67, but my 68 originally had an idiot light cluster, and when I installed the gauge cluster, I had to add the wires for the tach and the ammeter to my engine harness. I believe that there were differences in the harnesses based on the options on the car.
BL
www.chevelles.com/showroom/Ark68SS
