O/c mud bog truck

A good friend of mine is into mud bogging, he bought a truck from a nearby town that had s Cleveland in it and was known for kicking butt in the stock class. There was a few issues with the engine so he brought it over to get things fixed. When we pulled the heads we were surprised to find o/c heads, it also had the old trw pop up pistons. The pistons were .010 down the hole and were in excellent shape. We added a little more cam and the new gaskets and bolted it back together. That thing was strong and with the light weight of the c motor compared to the 460's he won his class 2 years in a row! He even ran the stock exhaust manifolds. I was of the belief the o/c heads were not the way to go till I seen this engine run.