If your bulkhead plastic is melted, consider changing to a 1965 bulkhead. I did so in my 1964 Valiant (1965 from a Fury, ebay). You only need to cut the opening 1/8" taller to fit. 1965 have big buss-bars to feed thru the thick ALT and BAT wires which often melt the "56 terminal" spade feed-thrus on other years (exc. 1963). But, also clean all the other terminals of corrosion. People are suggesting "bulkhead" because that is about the only place where light and starter wires might touch, unless your whole under-hood harness has cracked insulation, and "melted bulkhead" is a common problem.