Programming MSD - when should timing be all in?

I am not running a map sensor, though I certainly could. I have a Mopar Performance MSD-6 right now and I have no idea what the timing curve was. The new programmable unit has a switch wire that I can use to change retards so I can switch between race gas timing and 93 octane timing with the flick of a switch. I guess I'm going to have to play. I am seriously considering welding in a bung and adding an air/fuel ratio sensor as well. I want to get this thing running well.