on '68 Barracuda - this was simple to install and made a huge improvement over the existing wiring. Corrected dim headlights, luckily also fixed problem with one dodgy old headlight socket that it bypassed, and even allowed some brighter instrument lights. Plug and play-no splicing, etc. Best way to go IMO. I happened to order from Summit, but available elsewhere.
fwiw.
UPD-34263
Headlight Relay Harness, H4, Kit
(Mfr. #: 34263)
fwiw.
Headlight Relay Harness, H4, Kit
(Mfr. #: 34263)