You've got to see this...

And thanks to Curtis and Moparmadduck.
I am producing 4-manifolds:
RB-1, 413-426-440 big runners, single plenum, single or dual carb
RB-2, 413-426-440 big runners, split plenum, must be dual carb
B-1, 383-400 big runners, single plenum, single or dual carb
B-2, 383-400 big runners, split plenum, must be dual carb
Dominator carb mounts available.
Manifolds will come with stainless steel bolts and washers, hand cut intake gaskets that perfectly match, aluminum valley cover, powder coat finish std. but available raw for those who want to weld nitrous bungs, etc.
These are not on a production line. Each will be made to order right here in the USA by genuine Americans who take great pride in the finished product.
The performance of any manifold is determined by the total combination of the engine build and the owner's ability to tune.
Pat
PS....I would love to produce for 426 hemi engines. If anybody out there has a pair of wounded heads with integrity of the intake flange areas, I would be glad to have them to make up block/heads jig.