Here is the part of the article about the dimpling of the combustion chambers (and bringing the spark closer to the combustion)
Ross provided the forged pistons that Johnston and Milano modified in-house. "We did dimple the tops of the pistons and the combustion chambers to help atomize the fuel," he says. When asked about any empirical evidence that the dimpling did anything to actually help, Johnston referred back to a 409 Pontiac he built for a previous EMC competition. They tested that engine with stock-type chambers first. "It looked fat in areas and the combustion chamber had wet spots where it would puddle in there. I thought, 'You know what, I'm gonna try this.' Because I've seen some articles done on this but I've never seen any testing and nobody knows where to put these things, so I just kind of randomly made it look like a golf ball in the combustion chamber. We didn't do anything to the pistons on that motor." Between just the dimpling of the chamber and also changing the spark plug depth where the electrode would protrude slightly into the chamber, that engine picked up almost 40 hp and Johnston was sold. With the dimpling done to this 455, the pistons and chambers looked like fuel had never touched them. They were also able to run significantly less timing for best power.
I have no clue if it's voodoo or if it might have some good ideas in it.