I decided to do an upgrade to H4 headlights and add a headlight relay to my 65 GTO The conversion went great with no issues. The lights fit perfect and required no modifications. All I had to do to the relay harness was to extend the passenger side wires by about 4". I am sure that I probably could have routed the wires differently and it would have been fine, but I wanted them to run where all the other wires run under the radiator support. The headlights actually look stock, except for the blueish color due too the bulbs. The wiring harness seems to be the same that others sell for double the price. It all was very easy to install and only required a couple of hours of my time.
Here are the items I ordered and used.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
http://www.ebay.com/itm/262426012140...%3AMEBIDX%3AIT
Take care,
Dale