Don't hate me just consider me the devil's advocate......
I'm just asking the obvious questions that one would ask if wanting to buy these or research if there is a market to sell these to...

I don't get it? what are you going to put on the end of these manifolds?

carby turbo is a world of hurt, don't bother

so if it's for injection it will need injector bosses

plus why ask hy-flo to make it if you already have picture of one someone else is making?

plus making the plenum is the hard bit not the runners, so if people can make their own plenum for it i'm sure they can make the runners

plus i don't think there is a large market for this, carby's wont fit on the end and will be hard to support, injection is way more money than most are willing to spend