422 dyno fail

I think there could be a valvetrain control issue in the upper rpms of the OP’s build.
The bsfc numbers really tank up top, as the hp numbers start falling off pretty fast.
That in itself isn’t unusual, but the fuel flow is also stagnant for most of the top end of the sheet.
If there were an air flow sensor being used, I think you’d see the air flow was also stagnant...... or dropping off.