I put on the halogen (blue) headlights and found the passengers side light was dim. This is because the old wiring is not big enough to handle the current draw the lights need. You will also have problems with the headlight switch getting hot and cutting out.
You really need to have relays and and larger wiring. I built my own harness and relays for about 20 dollars and left the old wing in place.
Here is a link to my web page with part numbers, schematics and pictures: Relays for Halogen headlights
66Sprint200, I also did the LED lights on the gauges. BIG difference!
A code 66 coupe, Father~Son Restoration
289 4v, Roller Rockers, Electric fan
Performer & 650 Edelbrock
MSD ignition, Crane Cam
Tri Y into 2.25 Shelby side exhaust
T5 conversion, Hydraulic Clutch and 3.55 Trac Lok
CSRP SN95 Discs
<=== CLICK on the "house" to visit my 66 website!