a bit of an update....swapped the motor out and swapped in another motor. only thing i actually reused from the old motor was one oil lifter. this 'new' motor i installed new timing chain and dampner, new cam bolt, front cover gasket, new zzp alunimum LIM gasket and i also reused the flexplate as i need it for my 2750 zzp stall converter. the flexplate i notice no cracks.
the bottom line is, the metallic tapping is still there! so frustrating what it could be.