Does the junction box take the power through the radiator support to the light harness? My bird is missing the j-block and the wire is stretched fairly tight around the rad support.

Not sure what you're asking Rob. The junction block is just a simple threaded post for wires to connect to. There is no penetration through the rad support - other than the screw that holds the junction block insulator on to the rad support. Typically the junction block will have a pig-tail wire coming off the positive battery cable, and a wire connected to the horn relay.

Yr or car??? That wire powers everything in the car except the starter.

http://www.chevelles.com/showroom/data/500/medium/Original_Chevy_system.jpg