If it is your only vehicle, rebuild it stock. Multi-Carb setups are cool to play with if can afford the downtime for tuning carbs. Split manifold will give the illusion of more power because of the noise, but minor, if any power gains. A Petronix point conversion for your distributor is nice if you do not like dealing with points.
Find a machine shop that is familiar with 235 rebuilds. These days they are becoming scare. If the machinist frowns/winces or responds with, “What is a 235”? Run like crazy. As simple as these engines are, an inexperienced machine shop can easily screw it up.
Have new bearings installed in your transmission, that will quiet it down.
Thats my 2 cents worth of practical advise.
