Stopping the knock: Lower compression and ported heads...

I love the pushing the compression deal. He!!, I've even posted on other threads that I thought guys were leaving some power on the table. With that said, your issues have made me rethink my position. I thought you were trying to lower your cranking compression? If that's still the case, use the thicker gaskets you already have. I used some steel shims on a couple resto Pontiac engines with good results and they were iron on iron. But, that was in a era of decent pump quality fuel. I can't imagine using them with aluminum heads unless it's a race only application that would get torn down quite a bit. As you've said, the thin gaskets will jack your compression back up...:banghead:. Quench, no quench,.....I don't really know at this point, but you need to decide which way you're going to go, and just get her done.