Ok, so I am now starting to swap the tops and I noticed that my l26 i picked up with only 26k miles on it had an immaculate valve-train. Then I took the heads off and noticed and abundance of carbon build up and flaking all over the top of the pistons. Is this normal on newer motors? My old motor that seized up looked clean in the combustion chambers and piston tops. Isn't that ironic? Also does nay one have any good tips for cleaning the heads and block that mates with them?