Highest flowing sbm heads?

I'd be more than pleased with 9s.

Is having his own castings made?

yes, they are overseas castings, all the machine work to finish them( they come as blanks) is done at Bischoff. Very, very reputable shop.
Rod the. sets up the springs, etc, to your spec.
his brother Vic designed the ports from scratch, have 2.08 intakes.