Sometimes, when a head is milled, the pedestals are shimmed to provide the proper rocker arm geometry on a non-adjustable rocker assembly such as the I6 w/ hydraulic cam. What kind of motor do you have? Typically, an adjustable assembly will have enough adjustment built into it to accomodate the surface milling of cylinder heads without getting shorter pushrods.
John
[color:blue]'68 Coupe
250/C4, 221 Argentine Head
Breakaway Converter, 9", 3.50's/T-lock</font color=blue>