Tach problems SOLVED !!!

I had posted earlier about installing an NOS early tach in my 73. Found out it wasn't practicle. the wiring is completely different, they operate on a pulse right from the coil wheare as the 73 is more a low voltage thing. Anyhow I decieded to try my old tach one more time. I cut the hog ring ground (attached to 3 black wires) and put on a female spade connector that attached to an unused ground on the tach housing (thanks JW). I noticed a plastic adjustment or calabration screw on the back. I had just wired up a new flamethrower coil from LBC Co. so with the tach resting on the steering column and all wires connected I fired "Abbey" up. Guess what, everything worked ! I played with the adjusting screw on the back of the tach while idling and could adjust it from 0 to about 2 grand. i set it to about 900- 1 thousand RPM. bolted everything up and went for a drive. For the first time since I've owned the car, ALL GAUGES WORKED ! I had just installed the NOS speedo. and checked my speed against the RPM and everything seems correct. No bouncing needles, no guessing my speed, no banging on the Tach. Probably was a combination of a bad ground, bad connection at the coil and out of adjustment. I also bypassed the dash light rectifier, and my gauges can actually be seen at night, LIFE IS GREAT ! All you others with the later tach that dosent work, change that ground connection and play with the adjustment. Good Luck.

Congrats!