I installed a petronix in my point distributor while the engine was out being rebuilt and when the engine was reinstalled my tach does not work anymore. It does seem to wiggle a little when reved. What is my problem? Where is the ground so I can check that?

Can't help if it's a problem with the pertronix unit. Best I can find is their site. They have a 800 number. If you are refering to the gage ground, thought the 70s had a separate wire come off the back of the gage. http://www.pertronix.com/

Anyone else out there?