This is my first post... I have a 72 GSX clone (VIN says Skylark). 455 Stage 1 motor, with a hood tach. Not sure if tach is OEM or aftermarket. Car has 500 miles on rotisserie resto. I have driven it 400 of those miles. Tach has worked just fine until it stopped the other day. Light for tach stopped as well. I opened the hood expecting to find a broken wire from the coil. But, it appears there's more to it than that. There's a plugged connection. I followed the wires into a harness on the fire wall. I stopped looking and have joined this forum in hopes to gain some troubleshooting tips, please. I can grab some pics if it will help. Thanks.