Confirming that rsclassics' guidance to wiring an OER hood tach worked for me. Connected the gray wire to positive (ignition), black to ground and black w/ purple stripe to the tach wire at the distributor. I'm using an MSD Ready-to-Run. I must tell you, I was dead in the water before reading rsclassics post. Turns out I had the positive (ignition) and ground wires reversed. The light worked, but the tach would not.
