[Dwight Southerland]

Joe,
Assuming comparable compression ratio, there are instances in SBC Super Stock combinations where a properly shaped dish has a alight advantage over a similar combination with a flat top piston with valve reliefs. There are lots of other factors in that equation though, not just the dish vs. flat top comparison. That being said, the shape of the dish is critical for the advantage. For Stock combinations, the factory dish shape is a disadvantage in every situation I have seen.