Yea, I'm on the last bore and it's an '83. It's barely at min. spec so it's got a while. I was considering re-sleeving it and having it ported, but now porting doesn't sound like the right option. I think I can change cylinders up to '87 with 0 issues. '84 & up have a smaller reed cage, so I'm guessing there's a little more low end with them. Dunno power characteristics of each year tho.
I'm thinking a 38mm Mikuni TM with a Thunder products VIP (engine side venturi splitter) might be the way to go for the carb. Should give it the throttle snap of a 33mm without losing top end of the 38mm. I experimented with a home made venturi splitter (engine side) and it was more responsive on the bottom without even making the necessary jetting changes. I think with the flatside, I won't have to go as radical on the pilot and I can get a faster air flow. I'm already at a 35 on the pilot and would need to be a bit leaner with the venturi splitter if I stay with the round slide.
So I guess it's time to research and see if I can find the power characteristics of the 84-87's.
Lol, I'm already in the process of switching to the cartridge fork & front disk of the '88, putting an '87 swinger/shock for the better linkage system. I've got plans on switching the internal rotor for the '85-'86 flywheel ignition system, so I can power lights going street legal to bypass some local bs laws that restrict riding. Plus I'm using a '92 number plate & front fender. I'm literally converting this into a bastardized bike to suite my needs.