I put the 9.5PV and jetted it up from 55s to 59s today. The part throttle bucking is gone. I really didn't drive it far enough to tell if I could see what difference the PV made. Probably drive it to town tomorrow.
You said it lightly surged at cruise iirr.
That's the jet. 4 jet sizes at a time? Be nice to see one change at a time, like 2 jets @57 Awesome to hear it's gone, just keep an eye on the plugs though... that's a really big step in enrichment...and IF correct, means the carb is a hair too small. That would be suprising to me.