Cryo treating blocks?

So I've posted quite a few times regarding my rather controversial plan of a W9 headed factory 360 block. I was doing a little research and I ran across a post of a machine shop that partook in a competition. Long story short they crank out over 720 horsepower out of a factory magnum block without any block filler. They said they sent the block off for cryo treatment stating it makes the block 30 to 40 percent stronger. I have very little knowledge on it but what does everyone think on this topic? Also does anybody know somewhere that would do this in the Midwest (assuming they stand on the good opinion side)