What horsepower are you at? Heads and stuff? Are you out flowing the capability of an 800 holley? I dont think you should have to totally reconfigure an 800 holley to run it on most 454s

that is a old 800 carb(if oem 500hp) and was set to run on a single plane intake, you can try richening it up see where it goes, but you would be much better off with a quickfuel or a newer holley HP carb, far more tunability.

Yes old HP500 carb (# 9022). Just confused how it can be in the 13's until 3600 rpm then fall to 15's by 4000 rpm.
Mr. Maine, did not dyno motor but nothing special just tried to match parts for strong 5400 rpm motor. 781 heads with 2.19 intake 1.88 ex. ported, air gap (Hardin) dual plane, Holly 800, stainless exhaust, full roller short duration higher lift cam 112 LSA to enhance my 8.6:1 static flat top pistons. It does sound and pull nice so far.
Going to try larger needle/seat and high flow power valve and monitor vac on next run. I just can not see how I can be over powering a 800 cfm carb. How could I tell, besides swapping?
Any help welcome. Thanks all.

It almost sounds like the power valve isnt opening. What is your afr at wide open?

Actually, just breaking it in "The Old Fashion Way" No WOT pulls yet. only 4 hrs on the water. Trying to get everything right down lower first. 4000/4200 is max rpm running under load. @ 4000 throttles indicate primaries only. I have given it quick bursts to 5200-5300 and chopped throttles after a couple of seconds. It gets to 5200 almost instantly with 23 mirage prop. I want to get this lean problem resolved then tackle WOT.

Also, try a one inch open spacer if the dual plane divider goes all the way to the bottom of the carb. Some do some dont.

How will this help with my problem?

The divider can affect fuel distribution, not saying its your issue but the spacer is something to try. Some mainfolds have the divider milled down a bit, including the edelbrock aur gap i believe.

Have you made sure all the passages are clean, power valve, air bleeds, transfer slots ect?

Yes I blew all with carb cleaner then compressed air thru a small needle. Just ordered a set of .150 needle and seats and 4 door high flow 6.5 power valve from Holley.
I will re blow all passageways when I install Power Valve. Also ordered #80 jets just in case but that seems like a LOT of jet!
Still looking for more ideas/suggestions.