I have recently purchased a 1955 Chevrolet Nomad wagon. The prior owner had installed a Ram Jet 350. I would like to install a mechanical tach. In reading the RamJet specs there are two tach output leads, tach1 for mechanical and Tach 2 for digital. The harness is bundled and covered with plastic conduit. I can not find the Tach 1 lead. Does any one have an idea of where to start?

The only mechanical tach I've ever seen was on a 65 corvette, it was cable driven from the base of the distributor to the tach in the dash, same as the old speedometers were, no electrical leads. Now if your talking about a analog tach that has a needle sweep, that makes sense. Perhaps if use the term analog rather than mechanical in your research you'll have better luck.