SU throttle shaft question

["Alan Storey" <astorey@magni.berry.edu>]

Dear List,

I would appreciate information on the use of oversized throttle 
shafts in SU carbs.  I have a 65 Spit with a definite air leak at the 
throttle shaft on one of the carburetors.  I plan to rebuild 
these carburetors soon, and I was wondering if I should use 
oversized shafts.  Should I just have the bushes replaced if the 
shafts are not worn to badly?  Is that something I can do myself?    

Alan Storey