[blucar]

As always, "superreal" has spot on info for sensible performance improvements to a flathead engine.
True, I am running dual carbs, Offie Super manifold w/ 97's on the 59AB engine in my '36.
However, I had a 1953 Classic speed boat for many years that had a "built" 8CM V8 that had a AFB 4 barrel carb and a Mallory ignition. The boat was our family ski boat for almost ten years. I taught all five of my kids, and several of their friends to ski with that boat.
Never had any issues with the 4 barrel carb, which I can't say about the dual carbs in the '36. Dual carbs can be very temperamental.. I carry four sets of jets and the proper carb tools in the glove box of the '36 so that I can adjust the richness of carbs for different elevations/heat.