Alright guys, question. I recently picked up a 06 6.0 from a guy who a “senior master Ford tech”. He had the cab off and “bulletproofed” it ( head studs, head gaskets, egr delete, dummy plugs, standpipes etc). Anyways, the guy had the heads machined and he reused the factory pushrods, rocker arms and lifters. Truck runs great but at idle, I hear metal tapping from under the valve covers, other than that drives no issues and my first thought was bent pushrods or broken rocker arm. Anyone else think that the reuse of the oem pushrods with machined heads is the problem? Last truck I had, got studded and I installed upgraded pushrods and valve springs.