Hy Ruckin Chevy, it sounds to me like you have a bad connection in the positive or ground circuit, check all your large cable connections beginning with the battery. I have installed quite a few Pertronix conversions, and I have never had to install anything that did not come in the kit.
I am with 3B on cleaning EVERY connection in the path from the battery to the starter. This includes chassis ground straps, and the negative battery connections. If you have the repair type battery terminals just go buy new cables of at least 2ga or thicker.
