1987. I ended up seeing a thread with bolt size and pitch but no lengths. I measured out 20mm in length and just ordered some off eBay. I'll see how it goes from there. I'll hit you up if they aren't right and just have some more spare bolts. Can't have enough of bolts laying around, lol.
After looking at your diagram, I bet it's that long bolt n washer #29 and #30, but it also looks like a long spacer in between that isn't there on mine. Ah, I see this diagram is for a 2002, I looked at 1987 and it's different, doesn't even have a diagram for the rear wheel.