Absolutely stumped!

[dw2000ta]

A few weeks ago I made a trip to West Virginia and had a few decent pulls in the mountains. After I was unloaded I noticed a odd sound through my intake... And noticed a lot of black smoke under acceleration. Finally got to where I could track down the issues. Found out I had two bad injectors. Replaced those but the noise is still there and smoke is to.
Did leak down tests. No bubbles.
Checked turbo no leaks.
No obvious leaks in the cac
It only smokes past 25% throttle.

I'm starting to wonder if I burned a valve or cracked a piston ring.

What are some obvious signs of those? I'm still learning the 871.
Any other ideas as to the cause of the sound ( almost like a chuff but muffled) or the black smoke? Any other tests I can do?

Any help is greatly appreciated. Thanks