The difference in the measurements has to do with updates.
The 1986 shock is probably .5" longer. The 1986 dogbone is 1" longer and the swingarm is 1" longer. The 87 I'm not sure of - I've heard it uses a shorter shock and dogbone but longer swingarm, but I haven't confirmed this. The 88/89 have all shorter measurments.
86/87 springs are light blue, 88/89 springs are red from the factory.
If you need specific measurements I can get dogbone/linkage measurements and swingarm measurements. I have what I believe is an 86 shock redone for an 88 so I'm not sure if that measurement would help but could pass it on.
