You know the BBQ igniter sound at random from 1500 to 2500 rpm not under load.

Anyway I'm sure it's not a bearing or piston slap. But in the event I'm wrong and it goes boom I will either LS swap it (even if it's under warranty) or get rid of it and my lifetime Ford love affair is done.

I expect noises from my fox that has noisy roller rockers but if I put my pushrod 5.0 to stock it won't make any noises from the crankcase.

Big shout out to dasilva for helping out trying to discover WTF is going on with the thing. It's amazing that this level of service still exists in 2019 which is rare these days.