Interesting . . . Fred, your owner's manual wiring diagram suggests that the car originally had incandescent bulbs, as did my '71. So at the time yours may have been an upgrade to halogens as much as it was for the dual-bulb setup, especially since the H4 high beam isn't used. These days one can get halogen bulbs with the old-style incandescent bases, which is what I'm currently running. Yes, with halogens and relays the high beams are quite good, even for old eyes.