I can’t educate you on a whole lot about these engines, but I can add some insights. I have a 1950 216 and am using a 1953 235 distributor. A PO had it installed sometime in the past. I found out when I decided to do the points, plugs, wires , and cap. I’m guessing that the original distributor failed. The 235 distributor works fine. It also has the taller cap and rotor. Like you, I had to return some parts until I figured it out. The engine runs about as well as one can expect from a 216 that doesn’t appear to have any other work done to it.
