I have a 1970 Chevelle built in the Flint plant. I have looked at several CHevelle but all where from the GA (A) plant. The location of the tach hole in the firewall does not match where the assembly manual shows it to be. All the ones I saw were under the blower motor when the last revision made in the assembly manual shows it to be on the angled piece of firewall between the area where the blower motor mounts and the flat area where the power booster mounts. Does anyone have any pictures that I can use. I want to install a tach in the car and I want to put the hole in the right place.

There was a dimple marking the spot to drill the hole on my 70 Malibu.