Rich Idle AFR reading

I have been playing with all different idle mixes and never got it to where I want. I retarded timing to 5 btdc and then back up to 10 and still didn’t get it right. I switched to manifold vacuum to see if that would make a difference and still rich. So I picked up a fatter metering rod and put that in and now it is impossibly rich!!! At all RPMs. So I obviously broke something. I am just one size under the fattest rod and my carb is set at the #27 reference point in the manual for a 1405. Which is the leanest setting in the manual. I am thinking about a fuel pressure regulator, since all of a sudden after a simple rod change I am rich across the entire rpm range. The carb has only a 250 miles on it and was just rich at idle, now cruising etc I am 11-12 on the afr gauge. And I can only get to 15-16 on deceleration. I put back the old rod and the stock rod and both seemed to give same rich readings across the board.

So here is my plan, fuel pressure regulator set at 4.5 psi and move up to from 12 to 14 heat range champions. And start again. Very frustrated, thought the rod would do it.

Since at 7k feet above sea level I can only get 14” of vacuum, should I also change step up springs to something lighter? Not sure that will change anything. Btw engine runs fine has always ran fine, no real symptoms, except now I can smell fuel at wot. So whatever happened with a rod change knocked everything out of whack.