Hey guys, maybe you can help me out. My pops just bought a hi po summit HEI distributer for our 65 Malibu. I just have one question. There is a connection for a wire/harness that is marked ground/tach. Can any of you guys fill me in on this. I haven't been able to take a look at it yet, but my pops was a little confused, so I figured I would ask you guys.

The person my pops talked to at summit didn't know much about it, so I am trying to do some research. Everything is basically common sense, but we were both wondering about this. Also, if it is for just a tach, will any aftermarket tach work?

 

If this is the early style coil-in-cap model, then there will be a plug coming up out of the dist body with 3 wires, pink, brown & black. That plug plugs into the cap. The black one goes to the dist body and connects the coil to ground. The brown is the coil wire, which is also where the tach goes. Pink is 12V. All you really have to hook up to it is 12V ignition with no ballast resistor; the 65 will use a resistance wire in the harness as the ballast, so you can't use the car's original wiring. Run a new large wire, 12 or even 10 gauge, from the fusebox.

Nearly any aftermarket or factory tach will work correctly when hooked to the Tach terminal.