I don't know as I don't actively participate in big block stuff but i'm guessing he is running the 400 not solely because of it being low deck but more so because it has proven to be a better production block in the big block arena. To be honest it's still early yet and I glanced over the fact that he is using a 400 block anyhow, lol, but anyhow when guys have had failures and or want peace of mind and or making some good power they take the route of an aftermarket block.