power valve makes my 440 ping??

Oil consumption? Are you running a factory style PCV system?

Make sure your EGR removal isn't leaking, also given the healthy skim on the heads, make sure your ports aren't leaking at the bottoms under the valley tray. If you are pulling even a small amount of oil into the intake, you'll have detonation.

It could be that as rich as you were running, you have built up a pretty heavy amount of carbon in your chambers.

Just something else to consider.