Does Shimming the rocker arm stand affect
the lift of a cam for a 98+ LS1?

Do shims also affect the piston to valve clearance?

Just looking for a better understanding on using shims.

 

Shim's are used to adjust the preload on the lifters or to correct the geometry of the rocker. They do not change the lift or valve clearance. Example, you milled your heads .030 and dont have new pushrods to make up the difference so you shim the rockers up .030 to keep the preload the same.