[Formulajones]

I'm on the same page as Cliff, if you're hearing some sort of knocking noise while lightly revving the engine with no real load on it, you either have something outside rubbing somewhere, or you're simply hearing piston slap.

That piston issue should have been addressed when you had the engine apart. We could have at least eliminated that scenario at this point, but now as it is, I don't think you're going to get any clear answer or any reasonable solution to your issues. You'll just have to continue to monkey around with the thing and enjoy the experience.

Might help readers here if you posted a video of the noise, give us some live audio.