I agree the market is very small.

That being said, and since there is no water running through BB why not just come up with a "clean Sheet" head like a scaled up W8 (or Heaven forbid an LS3 (perfect port size for a 440) or BB Chevy style "non siamese" port that you could just use a Hemi cam with? Something like the Cleveland Ford CHI (or a scaled down predator) that flows 400CFM with great port velocity would be really cool. Just make it adapt to either an RB or Hemi exhaust port/placement

And Just sell the heads and a manifold as a package...one stop shopping.

At a minimum I would love so see a Scaled up W style head that has the valves on the bore centerline (Like a B1) with maybe a few degrees of cant in them similar to some of the best Ford/SBC stuff out there.

The bottom line is the generation big blocks appeal to is dying off, just like flatheads and Dynaflows. Not only that, Car culture in general has fewer and fewer spending more and more to keep things going.