I saw one last week at the Sturgis, SD Drag Strip running alcohol and he was shifting at 9335 RPM...
Wow, that guy gets my vote for "driver of the year" if he can control his shift speed to the nearest 5 RPM. I consider myself doing good if I can hit high without tossing the valves.
From the sound of your valve train pieces you should be good well into the 6000-plus range; just make sure your valve spring seat pressure (especially the exhausts) is within the specifications of the camshaft maker. I don't know about Chevy rotating assembly robustness.
