I measured the distance between the screws, and as best I can tell it's 7 13/16" on center. I noticed that the body has a bump out that's smaller than the actual light, and I'm not sure that I remember that on my '97 HB. If the screw distance is right let me know and I'll see if I can take a look at my old HB sometime to compare. I sold it to a neighbor, so it only lives two doors down.
Heath