1966 GMC pickup. V8 with HEI. Trying to make sure I buy the correct harness. Looked through the catalogs already. Just not sure. My new alt has 2 wires coming out of it, red and white. Does this automatically make it an external? I've got a GM HEI distributor. Idiot lights. I've been told you can just use 1 wire if it's got an internal regulator? Diagrams online looks like they sent the white to the idiot light, and the red to the positive on the battery clamp. I'm looking for a harness that will cover all this confusion. Plug and play. And hopefully under $100.