While the above quote doesn't tell you how to determine a redline--It is in fact something I agree with 100%. That cam and yours heads will be done by 5300-5400.
To ddetermine a safe redline requires taking into consideration the components of the engine, how they were assembled/machine/massaged as well as the actual power curve. Typically what I see on the dyno and how rapidly the power falls off after the peak will determine my answer. No need to turn your engine higher than 600rpm unless you "just have to" J.Rob