Factory console tach wiring

Hi all
Hoping that someone as some info for me
I'm trying to find the factory correct way to wire a console tach on a 68 dart 4 speed. Where the coil lead wire goes, if all the way to the coil where does it go through firewall, pictures would be great. where the ground wire is attached and where light and power wires attach. I'm hoping to be able to do this and make it as correct as possible
Thanks a lot in advance if anyone can help