As far as I'm aware the 1st gen tacomas don't have running lights. It might be an aftermarket set up if it has them. I don't know for sure how you would go about disabling them.
My guess it that they had to run power to a relay and then to the headlights if that's the case. I'd be interested...
I've got a K&N drop in in mine. I haven't seen a tremendous gain horsepower or fuel economy wise but I like the fact that I can clean it whenever I want. A detail a mans truck that has a K&N cold air intake on his ranger. He says he has seen a difference. But I have no clue how much...