Have the manifold in my hand but no way to take a pic of it. :banghead: The casting number is 2465847. The main difference between the early manifolds and the '67 on is the outlet. The '67 on outlet points down after wrapping around the steering box while the older ones have a 90 and point to the rear of the car at that point. They also have an extra hole in the outlet flange to accept the bracing that comes from the block for support. The big choke point on these manifolds is the ball socket on the outlet. Mine measures 1 1/2" across the opening. Looks to me like the outlet could be drilled out to get a 2" or 2 1/4" outlet with the use of a flat pipe flange and gasket. Most of the restriction is the ball itself. Hope this helps.