Converter upgrade worth it?

In my Dart I have a stock '74 360 with x heads on it. They are 68cc, I have measured to approximately 8.4 CR it has a xe268 cam with 3.55 suregrip, 904 transmission, 25 inch tires. Runs well now with a stock 1800- 2000? stall converter. Would I find a noticeable improvement with a custom converter?