2005 GTO - Misfire starting around 6300 rpm's

[Mobile Chassis Dyno]

Guys,

Please excuse some of things in this scan such as fuel trims for we have not done any tuning on it. Car was previously tuned from another shop. Trying to diagnose a misfire issue that I believe could be crankshaft or camshaft position related.

Cliffs.

LS3 Block
24x crank reluctor and Black CKP sensor. Has had 2 different reluctor wheels and 2 different sensors trying to diag the misfire.
2 different cam sensors.
Several sets of wires, Coils, and Plugs
All three cam sensor wires and crankshaft sensor wires measure .4 ohms or resistance from the pcm harness plug to the sensor plugs.
.020" air gap between the crank sensor and reluctor wheel.

Take a look at this scan I attached starting around frame 3285 or 1:22 time.

Look at the following

Low Res Period
Medium Res Counts
Medium Res Resyncs.

Around Frame 3335. The Medium Res Resyncs starts to climb.

At Frame 3367. Low Res Period goes to 1000 msec's and Dynamic Airflow, Cylinder Airmass, and Injectors fall off the face of the earth.

I have tried googling Low Res Period, ETC, ETC and can not find anything on it.

Any thoughts as to why this car is breaking up starting around 6300 rpms? It seems to be losing crankshaft reference for it misfires so bad it shoot fire balls when breaking up.

At this point I do not see it being tuning related.

[Mobile Chassis Dyno]

Log Attached

[nskaats]

Did you ever find a root cause for this issue? I have a GTO right now having the same issue, though it starts at lower RPM. Does the exact same thing with low res period and everything. It's a new engine the customer bought and installed. He also had to try three different crank sensors before it would fire the first time.

I have a feeling the reluctor has excessive runout. They only have a tolerance of 0.027" at most and I've had issues with this in the past. I always measure when building an engine, but I don't think that's common practice unfortunately.