This is a picture of the metal I pulled off the magnetic crankcase drain plug...

 

Some of it looks like pieces of valvetrain.

 

The engine was extensively modified +10 years ago.... ...these bits in the oil pan look like a valve-keeper and perhaps the metal piece of a valve stem seal....

mods include shaved ls6 heads, terra yellow roller rockers, double springs, hot cam, longer push-rods, double roller chain, high volume oil pump, etc....

 

Did these come out in an oil change, or do have the engine apart? If the pieces came out with an oil change, I would be pulling the valve covers.

 

....bits were recovered from the magnetic oil pan plug... engine runs without issue currently...

 

Hard to tell the exact dimensions of the parts, but looks to be either the tip of a valve spring or if there are the hat seals, you have one tearing apart.

 

...so I tore the driver side valve cover off..... no damage there.... terra yellows and valve stem keepers are all OK....no metal in the DS head....

 

this is a pic of the valve covers off..... I pulled one of the Terra-Yellow rocker arms off - no damage.

Should I just keep tearing it down?

....Not sure if I should take the heads off, if nothing is found up top????

 

If it were mine, I would to see the top of each valve to make sure everything is in place, so I would take off all the rocker arms.

 

That almost looks lifter related to me. I have seen the top sides of the lifter break off before. It also looks like the chunks came from something round. They look too big to be off the valves or keepers. If your rockers look fine, I would start looking a bit below them.