I just upgraded the Green '67. I got the relays from an F-250 over at the salvage yard. (I actually picked up three sets) I spliced them into my original wiring with no problems. Just be sure to clean all of the contacts in the light circuit, including the dimmer switch connector. (it is usually the worst). I also added a ground strap from the engine to the frame and from the frame to the core support. Made all the difference in the world... No reason you can't do it this way if you take your time and do it right. For anyone who doesn't have the time, or doesn't want to take the time, buy aftermarket....
LockDoc