Head Gasket replacement - Rocker Arm Shims?

After getting machined Heads will I need Rocker Arm shims? Or can Machine shops make up the difference somewhere?

3.4L, 2003 Pontiac Montana

They should not have milled more than .25mm(.010"), If so, the head needs replaced. No need to shim anything, bolt it on and go, the lifters will handle the change.

They should not have milled more than .25mm(.010"), If so, the head needs replaced. No need to shim anything, bolt it on and go, the lifters will handle the change.

Thanks - the question came from reading the manual and it says you can add up to two .010 shims to the rocker arm if the head was reconditioned, anthing more than two dispose of the head. It told me to measure the valve stem height but I assume the machine shop would have told me if I needed shims.