Need pic of tach wire coming out of the firewall

[troy.70R/T]

I need a pic of where the tach wire comes out from under the dash (on the firewall) My car is a 70 B-body 440 with air. the new tach harness I bought has a grommet on it I would nee to drill a 3/4 inch hole in the firewall to use it. I am just wondering if the hole already exists and I just have something hooked up wrong. The car orogonally had a tach so I assume that the hole should already exist.

[68charger383]

http://www.dodgecharger.com/forum/index.php/topic,4240.0.html

Great thread which should help