How far to rev this 273 commando build

The Commando even with the factory cam was a revver. Not a lot of grunt down low (torque peak at 4K!), but it loves to wind. Look at this chart from the factory brochure.
Screen Shot 2019-02-06 at 5.03.08 PM.png

Don't be afraid to see how it likes it at 6K -- it's overbuilt as hell for the displacement.