Anybody with some aluminum and a TIG welder can mock up a prototype manifold for dyno testing. Once a final design is perfected and tweaked on a dyno, anybody with a CNC printer can turn out production pieces by the thousands. Casting is so 19th. Century these days!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!