I have a 02 sportster the diameter of the switch housings are larger than the diameter of the handlebar in that area. Is there a form of shim that could be used to accommodate the difference or do I need to just buy different handlebars? Thanks in advance.

 

What kind of bars do you have? Stock Harleys use bars with a 1" diameter clamping area and 1" diameter area for the controls.

 

Sounds as if your bike has non-Harley bars. Harley are almost alone in using 1" diameter bars, most other brands use 7/8".