Installed new coil, now the tach acts funny

Believe me electrical can be confusing. I threw my hands up and our 67 has sat for a few years now.
I always ASK, well almost always lol, before doing something that I dont understand, OR something that could affect driveability. There are LOTS of aftermarket goodies out there that alter/cripple the way that these mopars work unless done properly or modified.
There is another electrical thread going on that I cringed at as the OP posted "he hired a mechanic/shop" to install elec ignition and now it doesnt run worth a ****. Licenced mechanics arent electricians lol. Anyway sorry for the ramble, glad ya got another one ordered. You meaning tach?
Perseverance pays off. There are a few electrical whizbangs on here that will get you on your way.:thumbsup: