Spark ply wells filled with oil/ now cleaned has internment miss

[20redfire03]

A friends Mach 1 was eaton swapped, ran great for a few weeks including passes down the 1/4 mile but a week or so ago he discovered his spark wells on his driver side head the back 2 wells at least filled with oil. What would cause this to happen? He has cleaned the oil out, replaced/cleaned/rebuilt the COP and replaced the plugs. He had also installed a JLT catch can. I don't think the oil issue is as bad now but has a misfire. I don't think it's throwing codes either. Over 3k it acts fine along with crusing speeds and under load.

 

[20redfire03]

One of the spark plus wells has filled with oil again? Is there a gasket that could go bad to cause this?

 

[NastyNate420]

Yeah theres are gaskets that are prolly shot...you have to remove the valve covers to replace them.
If your still having a missfire problem after that then Id look into new COPs

 

[20redfire03]

That's what another friend thought and getting a pcv valve rated for boost as well. He did say he had new valve cover gaskets, are these gaskets part of that or separate?