I have spoken to Barry in the past about this and for serious power he prefers to slightly modify Art Francis' Blue Thunder castings.
They're how it got him over 700 on pump gas.
My out of box CNC'd Shelbys are 320/230 @ .600 (which is where my cam works) and they clearly out perform my ported iron Med. Risers which had 2.250's and 1.75's.
Ring gears? We ALL got stinkin' ring gears!
