Bumping bullets up is possible, but not practical, imho.
With rare exceptions, the moulds sold for .38/.357 cast .358 or bigger, often quite a bit bigger.
First thing to try is shooting the bullets you have. They may work fine. If they are inaccurate or lead your bore, you need to try bigger bullets. If you want to buy them, we have custom casters on this board who will set you right up.
Me, I'd buy a Lee six cavity mold and go to casting. I bought a 356-153-2R on closeout last month that drops in the .358-9 range w WW metal. If I needed them bigger, I could get another thou or two by adding some antimony to my alloy. No need to do anything more to them than cast, inspect, and lube with Liquid Alox.