""Most say that 8-10 jet sizes difference keeps a good balance (assuming PV up front, not in rear)""
- My carb setup came with a 14 jet spread front to back from Quick Fuel. My current jet spread is 13. I have noticed a .2 A/F change on the primaries with only a one jet size change. This carb is very sensitive.

I was looking back thru my charts and I found that this 11.8-12.2 A/F spike from cruise to WOT was not as bad of a problem when our outside temps were in the 60's-70's. I was getting A/F readings at the 12.5 A/F mark before the Summer heat hit. Maybe I just need a leaner cam adjustment during the Summer time.

""I wonder whether the mains are "spitting" fuel at 3K and 22" vacuum. I realize now that the mains are flowing some fuel under these conditions and I am again pondering the emulsification jets.""
- Have you tried delaying the mains to see if the problem moves up in the rpm range beyond your cruising speed?