We've used an early 4500 440-3 that appeared to be just a plunge cut, 4150 version. It was cut in 2 horizontally, the clover removed, welded and blended. We eventually swapped that out for a 440-3X both these manifolds had distribution issues with cylinders # 1 & 2 running leaner than the rest. We improved this with an old school trick of grinding a couple of grooves at the entry to the runners of 1 & 2.