A buddy of mine has a 235 in an F-20 tractor (old homebrew conversion). It's got the stock intake and exhaust manifolds both turned upside down, updraft carb and an exhaust stack. I would be willing to bet you could just turn a Fenton or similar dual-carb manifold upside-down as well. The issue will be the exhaust. I'm not sure if you'd have room to run the exhaust in the stock location.
