Quote:

Anytime you have a custom engine with milling on heads and block etc, you will have to shim the rockers to achieve proper geometry.



WRONG, cutting the heads and the block does NOTHING to valve to rocker GEOMETRY , you have to cut the ROCKER STANDS to affect that.

Shimming rocker shafts because of aggressive head and block milling is the WRONG way to correct for the problem created which is PUSHRODS that are now TOO LONG ...

The shimming the OP is talking about is shimming BETWEEN the rockers to center the rocker tips on the valve stems .