Re: Zetec valve adjusting shims
The Zetec engines should not have shims. The valves and the tappets are precision-matched so they don't need adjustment shims, as there are no hydraulic lifters, and the lobes on the chain-driven cams are cold-hardened for long life. This ensures that the valve clearances can remain in spec for 150k miles or better.
As far as new cams....I have not done this so I could not tell you.