Sorry if my reply came off a little harsh, but your thread title leads one to believe that the HP gain could be attributed to a CR change alone, and my point was that that was not the case ( although stated poorly by me ). As stated in this thread, I think a quench change had partly to do with the improvement, and maybe piston top reshaping, etc. I to, appreciate all your hard work and sharing the results. Just wanna clarify to all that adding a point to your CR my not automatically have the same positive results as you did. Making multiple changes is my personnel nemesis, as I don't have easy access to a dyno - and 2 - 3 trips down the track once a month can give pretty limited info.