the fan should provide sufficient cooling if it's within 1/2 - 3/4" of the rad and pretty much centered on it - another thing that may affect cooling is a pressure cap, your 46 rad may not take a pressurized cap without having the fill neck replaced, but the 235 in 55 would have had a 7# cap .... you'd need to check around hot rod parts places for a shroud that would work for your particular configuration, or fab one yourself, but set up everything else first before you decide you need one .... in my experience, the 235's tend to run cool if you let them, a 160 stat might satisfy you
Bill
