Torque converter

Any neutral balance 904 converter will work if you're using the magnum balancer and flex plate. But what stall speed would be best depends on many factors, like camshaft choice, rear gears, tire size, etc, etc.
Behind my 5.9 is a 904 from a '74 318 Dart, I'm running the stock converter I got with the trans. works fine for everyday driving around.