As a general rule, if you can wiggle the end of the shaft and feel the butterfly closest to that end,
or even see the butterfly move, the end play of the shaft is too much.

This will cause a vacuum leak that cannot be overcome with jetting. Also the butterfly(s)will not consistently return to the same place at an idle
and as a result, you will get an erratic idle speed.

I fab my own bushings on my lathe and have a special ream with a pilot to bore out the shaft bore. This is after I grind off the staked end of the butterfly screws so the screw does not break off on removal.

I hand fit my bushings to be able do drive in the new bushing and then steak the outer end. Then the bushing is reamed for best fit to the shaft.

It is rather technical in process and I have re-bushed 5 carb bases just this week.

If you have the passenger side primary shaft bore bushed, you will have a nice working carb.

Pm me if you would like more info, David.

ps, pic of how to test the end play: