Bronco Nose Change

Would a nose ( Hood, fenders, grille, bumper ) from a 89 Bronco bolt up to a 86 Bronco without any headaches or customizing?

The grille would seem the most problematic. (I seem to recall the 85-86 years being just different enough to be a headache.) I think the front turn-signals are positioned slightly differently from the 87-89. I don't think the bumper/hood are going to give you any problems. (I'd check the latch clearances, just ot be safe.)

You could replace the entire front clip (including radiator support). Then you would not have to worry about the grill and turn signals and everything.