I wouldn’t recommend using more then one shim; solve the problem not the symptoms…..
Why do you measure the length of the filter?
The filter has big o-rings in both ends; it has to be a lot out of spec (several mm) to make any problems. It’s the canister depth that counts.
Puking oil: http://www.advrider.com/forums/showthread.php?t=211923
Shimming oil filters: http://www.advrider.com/forums/showt...=286618&page=1