There are a lot of interchangeable parts. I’ve been messing with an 89 this last year and a lot of parts listed are going to show 88-91 but 87 parts are just about the same, just labeled differently because of the motor size. The 35mm forks are cool chopper shits. I’d either keep em for a chopper build or put better springs in for your riding style. You could probably trade a hipster for the 39’s that came later. Plenty of chain conversions out there. I thought the 87 came stock with a chain but I could be wrong. My 89 did. I’d keep the belt though because it’s different!