My expert manifold splitter, welds in a block off plate down inside the hole towards the back, to block off the back three cylinders. (that's looking straight down inside the 235 exhaust, once you pulled off the intake).
Step two, he blows a hole somewhere along the side on the back half between the center and the firewall, depending on where you want aft pipe to locate.
Finally he welds on a cast iron elbow over this hole. This elbow has a flange to bolt exhaust pipe to. This iron flange is getting to be difficult to find now days.
Also, he welds closed the heat riser baffle so as not to constantly blast the bottom side of the intake.
I guess now all you need to do is find a really good welder of cast iron in your area. My guy is in central Calif.
Best of luck.
