I have read the thread from "Gotenkusu" and have a similar, but different problem......same exact engine and carb.

Let me start simple and move up from there....On my ignition coil there are 4 wires. Standing on the passenger side, looking at the coil on the left side are two pink wires and on the right side is a yellow and brown wire. With the car running, all 4 wires read 13-14 volts. If I unplug the yellow wire, the tachometer reads 0rpm, but plugged in it max's out at 7000rpm.

Is it just me, or are the voltage readings from the ignition coil reading incorrectly? If you apply 12 volts to the tach, it's going to peg out, right?

This is a new ignition coil, but my old one did the exact same thing. The car runs, idles and drives just fine.....it's just the tachometer signal dont seem to be correct.

What could the problem be?

 

thats easy bud...Its the tach...its old lmao theres a site for camaro parts if your going stock and theres nice replacments get the diamiter go from there... just the gauge! or you can put a risister in it! play with them till the readings right