I saw a test on them in a magazine where they got 500 hp with a stock 5.0 short block with them and a big ass cam. I've read lots of good things about the work John Kasse's done, the guy's a whiz with Fords. If I had the money and was in th emarket for heads and wanted the best, those are the best you can get for a windsor headed small block. His heads are also marketed under Ford Racing's name too.
I thought the exact same thing when I read the the specs on his entry, he specd a set of CHI (Cylinder Head Innovations) heads for his small block entry. Why didn't he use the ones with his name on them? When he won the big block challenge last year he used the SCJ (Super Cobra Jet) heads that he developed. I have heard a lot of good things about his new small block head though.
May be cause his heads may have been outlawed by the rules. Can't say for sure, but I do know that the rules for the Engine Masters don't favor Fords. He was going to build a 400 with his heads but couldn't swing the intake problem ( no suitable intakes out there for what he was going to do with the 400M)