Apex problem at 7500rpm

[MrSled]

I think it is the stock head gasket thickness. Just dished in pistons. It Stoll runs like crap. But the tune allowed it to rev higher. Leaning it out.

You need to get an AFR gauge and see what the engine is actually running at when it falls on its face.... those numbers on the tables are setting for the PCV to shoot for, it doesn't mean it will hit them spot on.