If you are not monitoring knock. I would start with your peak timing at say around 17-18 degrees under full load. I think you can find the data on the timing maps on the ezls. To give you a starting point. If you want to be more aggressive. Timing is one of those things that you really need to be on a dyno to do properly. You can do it without one but you better be conservative.
At duxthe. How does that thing feel at 18lbs of boost. You should throw it on a dyno to see what kind of power it is making. I am really curious. I am surprised that the 40lb injectors are handling that. I was maxed out on 440cc at around 10lbs of boost.