whatever it is stock. honda wanted a specific rpm to compliment the power curve. you changing it is gonna put a dip in your curve. when u get aftermarket cams then u mess around with vtec.
The best thing to do is place vtec really high up up say 7000rpm then run the car and when there is a dip in the power curve move vtec to that point. Usually ends up being between 4500-6000rpm. On a stock engine its best to just leave it alone but the more modified the engine the more it can benefit from this change to create a smoother power curve.