orchidski,

I bought a 12v tach at Advance Auto for under $30 (on sale) and it is mounted to the steering column (6 cylnder 54 Chevy truck). It is between 3-4" in diameter and has plain numbering. AS I recall it had clear installation instructions with about three wires (one for alight) People who do not know what is original think the tach is original.

Brendan,

What does "proper number of lobes" mean? Obviously, a rare case of dumb luck got me through this installation.

Tim