Hi Marc.
While I run an '81' it is pretty much the same engine as yours.
Elevation here is around 1500' ASL or so.
Main Jet; book calls for a 320, I run a 280 with the clip in the 2nd groove from the top. I dropped to a 270 a while back trying to get a plug fouling problem under control but that turned out to be a weak ignition issue.
Pilot jet; book calls for a 45, I was running it but dropped to a 40 to clean up the bottom a bit.
Airscrew; book calls for 1 and half turns out, I run 2 turns out.
Hope this helps!