I was up there recently with my ’01 YZ, rode at 8k+ elev. (Rampart Range).
I ran a 40 pilot, clip # 3, and put a 160 main in.
Ultimately I would have like to have tried an EJQ or EJR (stock is EJP) needle and maybe a 38 pilot because it was still a bit fat down low, but ran pretty clean once it was on the taper. It started very easily, idled clean and didn’t want to stall at 1.25 turns out on the idle mix so maybe 40 was the right pilot.
I dunno, maybe clip # 2 would have been better as well, but I think # 3 is real close. I’d rather ride my bike than work on it and just lived with the fat spot.
Hope this helps.
You may try this question on Thumpertalk, there are several Denver area riders that frequent that board.