id sooner put the right carbs on, the nc 23 and nc 29 carbs have diffrent parts inside anyway. for a start the nc23 has adjustable float height, the nc29 doesnt. ive always thought with things like this, the bikes designed to have all those parts to fuction properly and efficiently, from a design point of view, if it aint broke dont fix it. though i could be wrong.

you can adjust the float height...you just have to be brutal
they work much better than the 23's carb set up...
downside being,u need to get an airbox to fit
i modded a rep nc29 hrc raim airbox to fit,with a stock set of nc29 downpipes(withe restrictors)gained 2 seconds a lap at phillip island with that...
stimpy

Does the clutch and brake lever off a 29 fit the 23?