Ok well, I have a tach on the car now it just doesn't work too well. It shows 3000 RPMS anything under 3000. Above 3000 it seems to work.

I haven't dived into it yet, I'm just trying to gain an understanding of how it works. It's a regular ol' autometer tach. So it mush be driven by one of those magneto adapters?? FYI this car was built in the late 70's.