I agree - without some more development, an L6 manifold is definitely going to have some distribution issues, typically #3 & 4 rich both by being closest to the entry, and also get most of the drops that fall out of suspension. For now, the hot cylinders (#1 & 6?) are the safety target. I've seen best power as lean as 13.2 in NA motors - but those had excellent (even) water temperature, high swirl chambers, tight quench, etc. For a turbo, as long as you trust your anti-knock system you can run closer to best power since the extra gas isn't needed for safety (or at least not as much). Cooling the chamber with gas isn't the best method, but if it works and you have nothing else it's better than losing 1 hole out the exhaust.
