I someone like and look for a velocity stack for the Holley NH i can recommend Patrick O'Leary in Ballarat, Victoria, Australia who makes them in different sizes. http://www.velocity-of-sound.com/commerce/search/products/?product_id=VS39_56&merchant_id=2107
I had to make a small adapter due.
very nice ! i take it they will live together on a home made manifold, lets see it