Interesting Weber jetting

[Eljaro]

My 48 IDA on the 427 C/O are behaving much better now.
I have the #60 idle jet wit the #60 idle holder which seems to be definitively the best option.
The emulsion tube is self made.
Actually it is a F7 sleeved to have a larger outer diameter (8.2mm) and the inside drilled out to 3.5mm with all the holes an F19 tube has, only 4 more at the middle position.
So it is an F19 emulsion tube with 8 holes at the 3rd row from the bottom instead of 4.
The main jets are 125 and the air corrector 135.
Strange jetting that is, but my O2 sensor still shows rich all over the range, even on WOT.
It did lean out at WOT when fitting the 200 air corrector. I have not tried anything intermediate because I dont have any.
And now what. Even smaller main jets?
I am thinking that the signal is too strong and it is drawing too much fuel for the air the 37 main venturi lets the engine breathe.
Would a larger main venturi, say 39 or 40 lean out the mixture and get the air fuel ratio to a correct value?
I have an Os sensor welded in the exhaust where the four headers meet and I am monitoring always when driving and with load on the engine.
The engine is pulling very strong, revving up to 7000 with absolutely no hesitation at any RPM range.
Unfortunately all the driving before with the over rich condition has damaged my rings and I will have to replace those. But before I do that I want to get the Webers tuned right.
I would appreciate any help from the Weber specialists here.