If you can get it to 16.2:1 at the egr sample phase and not stall, it will pass
Seriously, NOx lowers below like 12.5:1 and rises until ~16:1 then falls like a rock again.
If you have a longer exhaust duiration cam, you may benefit from "self egr" that is, the backpressure in the exhaust, with a longer exh duration, leaves some exhaust in the chamber. This exhaust is inert and takes place of the space a volatile charge can occupy. The fact this inert "mixture" cannot burn, lowers chamber temps
Another thought is to retard the timing a bit to get the combustion event to occur closer to the time the exhaust valve will be opening, thus lowering combustion chamber temps below the magic 2500* mark, which will also reduce NOx.
Without using one of these methods to lower chamber temps, you wont pass NOx, sorry. FWIW, if you try anyway, My guess is 2300 ppm
Jim