Okay, the base circle on a 1998 F-body camshaft is 1.551 for what its worth.
Called Comp and they say that their base circle is 1.509.

1.551 - 1.509 = .042" or .021" per side

I guess I need only .021" milled off my rocker trays. The tech rep at Comp says that they recommend the 7.400" pushrods for all the LS1 engines in stock configuration.

Okay, next question, how much does aluminum grow when it heats up to operating temperature. Since aluminum grows faster and further than steel, makes me wonder how much valve lash you lose at temp.