You didn't make it clear whether you need a complete harness or just wiring for the alternator.
While I commend anyone who makes his own harness, the time and expense will probably make you wish you had bought a harness. You can get
this harness from Hot Rod Wires for less than $200. I consider my time worth $50 an hour. There's no way I could put one together in less than 4 hours if I did happen to have all the correct sizes and colors of wire laying around.
I used this harness in my '56 and was very satisfied with it.
