[OldsBuickGuy82]

Yes, the grill is different, I would think it would fit though. I would look for an 88 grill myself, just to make it look correct.

The headlights on an 1987+ are swappable between both cars as far as I know. The way you described the lights on the 98 makes me think it is an 1985 or an 1986. The lights became full units by 1987. I have no clue if the older set up will work in a newer car.

The fenders should be ok too from what I know of them. To the eye the only difference I can see is the decals and crome...Should be fine

The rad should drop in fine unless it was changed from year to year, I once put a rad from a Delta Eighty Eight into my Ninty Eight Regency. It was the same year car so you might want to check that out with a professional first.

Good luck!