Shims go between the ROCKER SHAFT AND THE ROCKER STAND (head) , when you deck a block or heads are you CUTTING THE ROCKER STANDS ????

If the answer is NO then why would a person shim the rocker shafts to make up for decking the heads and block ? Why , because they are a

And I think you misunderstood Hughes or he misspoke , changing the base circle of the cam is NOT changing rocker to valve tip geometry , again , the base circle change does not change the height of your rocker stands so it will NOT effect rocker to valve tip contact. the fix there is a LONGER PUSHROD.

If your rocker to valve tip geometry were off and required a LOWER rocker stand postion to correct it the same line of thinking as ADDING shim under the shaft would be to just run a SHORTER pushrod ? NO , you would have to MACHINE the rocker stand shorter.

What you have done MAY require a SHORTER PUSHROD , PERIOD , END OF STORY .

MP sells ADJUSTABLE length pushrods , why , to FIX the above scenerios , except for lowering the shaft ....