GMC_DUDE

I have nearly the same setup, although with a GMC truck, so maybe I can help. It does sound like fuel starvation. The reason I say this is that when I installed mine, I had fitment issues with the extra fuel pump, and was told by MC that it was OK to drive without as long as I stayed under 4500 rpm. Since your ping is at high rpm, this makes fuelling issues a prime suspect.

1: Did you replace the in-line fuel filter? A clogged filter will starve the engine when fuel demand is high.

2: Is the extra pump installed correctly? My memory is vague, but IIRC, somebody put one on backwards a long time ago. That, of course, won't work.

3: Does the extra pump actually run when the engine is running? You should be able to tell by reaching underneath and feeling it while the engine is idling. When I installed my kit, GM had changed the wire colors on the harness, and if I had followed the provided instructions, the pump would not have worked.

4: Is the small rubber hose from the fuel pressure regulator (that part you had to take off the old manifold, and where they warned you about not overlooking an o-ring) routed correctly? On my instructions, this portion was missing entirely, and I had to call MC and ask how to hook it up. But that was 7 years ago.

5: If all else fails, call Magnacharger. They are, or at least were, very helpful.

Above all, do not make any additional modifications (extra pumps or regulators, PCM calibrations, etc.) until this issue is resolved. Something is definitely not right, and arbitrarily adding or modifying things will only muddy the waters and make troubleshooting much more difficult.

Good luck, and I hope everything works out well soon.