Go with the MAD kit. Awesome. Here is a link to the information when I did the conversion on my 71. Unfortunately I did not measure the voltage at the headlight with the stock arrangement. After the conversion I have 13+ volts at the headlight. It takes a great load off the under dash wiring.
http://webpages.charter.net/perfmark/cars/chevelle/headlightrelays/relays.ht m Mark 71
