What type of tape?

If trying to look original, I would use non-stick vinyl tape like Mopar used. However, I am more "resto-mod". I have used PVC tubing, from SPC Technology or Alpha. Search for "PVC-105" on ebay. Various sizes, black or clear. However, works best with unterminated new wires. It is smooth, so much easier to keep clean than split loom. My 80's M-B's used it everywhere, for both wiring and vacuum tubes.