I updated both my 64 Chevy suburban and my 65 GMC pickup with with modern SI-10 alternator, HEI, and Halogen headlights on relays... Most of the OEM wiring was marginal, at best, so I went for a PAINLESS wiring 18 circuit harness for the suburban... took an entire weekend, I work real slow and carefully, I detest doing things twice... and I have the circuits needed for all power accessories, should I wish to add... the wiring is top-notch, 600 volts capacity, all labeled and the tech support was real good and fast, for the few questions I had... A little expensive, but it looks better than factory, and so far reliable...
Good luck!
