one basic problem with his setup is that the polished, very shiny alum shroud plate that the fans are mounted to is too close to the rad fins for any air flow thru that area----------

another-it looks to me like he has a temp sensor in the LOWER corner of the bottom tank-------at that point the water IS COOLER so the fans won't even be on until it gets HOT down there-----

3000 CFM isn't enough air flow to cool a big block