[Purrybonker]

I'll not be helpful, but I'll get you a bump at least...

I ran a feed directly off the back of the tach and terminate it with a marrette/elec tape under the dash when not using the LM-1. I don't remember which lead/contact it was on the back of the tach, but it seems to me that it was kinda easy to tell which one to plug into once you pull it out. If in doubt just look for the contact that gives variable voltage with changing engine RPM.

My LM-1 varies from the dash tach by about 300-400 rpm, BTW. Nice little side benefit of the LM-1 - allows you to calibrate the dash tach....