I have a 97 Legacy that has the single all in one headlight/side marker lights.

My son's 98 has the headlights that are seperate from the side marker. His are much brighter. The reflectors are better and the lenses are clear. Mine have those lines all across them.

 

Will the head/side marker lights from a 98 or 99 Legacy work on my 97 with no mods?

I doubt that anyone on this forum has done this swap to be able to give you advise.

 

I have seen both, and think they are very similar in size, so maybe interchangeable. The fenders and grills look the same, so it is worth a try.

 

Before looking around a wrecking yard for 98 or 99 lights, you may want to try swapping your son's lights into your car on one side to see if it will fit. I don't think there is a lot of hardware that holds the lights in place, so the swap process should not take long.

I did the swap about 4 years ago. Recall the bulbs are different and can't be interchanged. Also I replaced the plugs but can't remember why. Maybe the original ones were melted. Still have the car, a 95 and I think the headlights came from a 98.