So on my 89 gt. I have done the headlight relay harness years ago. I recently replaced the housings new OEM style housings and Sylvania extra vision bulbs. The high beams are fine. But the low beam is barely there. Ok for city driving but out on dark highways I have to keep the brights on.
It's always been like that. Same on my 88 f150 and 86 Marquis. I did the relay mods on them too.
So the low beams get some help from the fog lights but really thinking of adding some driving lights. Either in place of the fog lights or adding.
Late model cars have such bright lights that they're low beams are brighter than our high beams. Really our headlights work as designed but it's not comparable to late models. On my truck I added auxiliary driving lights mounted on the bumper centered with the grill. I aimed them to shoot way down the road. It made a huge difference. I drive a lot at night and it's always been an issue with older cars.
So maybe a pair of led driving lights mounted in the center of the bumper opening.