Tapping Really bad between 2300-3500 RPMS... Not for sure??

[fun240]

I rev it up to this point. im running mobil 1 on a rebuilt KA. It just taps really bad, like all my valves are hitting the top or something. I had it stroked and board while rebuilding it... Could this make the tapping? If someone knows anything like this and wants to hear it, ill be sure to get you on the phone to diagnose whatever it is if u have experiance with it... I want to put this KA in a frontier but i dont want to if this is a major problem. thanks

[fun240]

Anyone know anything about this???

It only makes this sound between the specified RPMS

Sounds like all my valves are hitting the top of the valve cover... Or something...

I run 89 in it, all the time...