I wasn't sure wich forum to put this in, but I knew the 61-66 would cover points.Anyhow, I need to check dwell and rpm on a....., um,..... um...... ,chebby (not mine,ha ha) I'm getting old and my memory isn't what it used to be. My tach/dwell meter has 2 wires, one green and one black.

I haven't used it for probably 20 years or so and I can't remember for sure how to hook it up. I think black goes to ground and green goes to pos. side of coil. Is this correct? I actually thought it was the neg. side but figured I was wrong.
TIA!

 

If green wire is the pick up side & black is ground, green should go to the - side of coil which gives the "break" or Dwell time in degrees the points are open. It is also the side that fires the coil to power the ign spark through the cap. . . .

If what's left of my mind is correct & the Blowtie is an 8 cyl you want between 28-32 degrees of dwell with 30 deg being the median

FBp

 

Right on Pete.

And if you are lucky the distributor cap might have one of those little doors on the side so you can adjust the points with an allen wrench while it's running.

 

Thanks guy's, like I said I thought it was the - side, but the more I thought about it I doubted myself. Yes the chevy has the "door" on the distributer.