I ordered a compact graphite iron 4.500 bore wedge block from Billy Mitchells (SP?) company when they owned or where in partners with World Products, I waited a long time before they cancelled making them due to not having enough orders.
I had placed a order with Dave Koffel for a Koleno high nickel cast grey iron block and ended up cancelling it when he called to say it was ready to ship, stupid me One in the hand is way better than one on order
I placed another order with Dave later two years later and got it several years later Dave had said that casting iron Mopar race blocks was a black art according to what he had seen and heard while working at Chrysler and seen later on both the Koleno and World iron blocks
I have talk to the guys at Chicago Connection for another iron block but I think I will wait until they have several bunches machined and in use before stepping forward on them