Building a 408 with IndyBrocks

I didnt know those Indybrocks didnt come CNC ported from indy. I remember Indy claiming they went 306.
The CNC version has that 300+ claim.
http://www.indyheads.com/images/15.cat2014.pdf
FWIW, the way I read the site, all head pricing is without porting no matter the head.
(There is a lot to read, I just skimmed.)

Does anybody have or KNOW if the Indybrock head does what they say cfm wise?