Depending on how big your main air bleed is, you could be cruising on the main jet at 2800. If you are on the booster at 2800 then you need to drop the primary main jet to get the cruise AFR where it needs to be.
If you are still on the T slots, I'd drop down to .048ish. If you get on the lean side of it the next time you swap in some brass you can always just pull them back out and open them up a bit. It's easier to drill out one set (if you can) than to keep using new brass to go smaller.
Soooooooooooo...if no one has told you how this works I'll give it a shot.
On a Holley or Holley clone, you need to set your cruise AFR with the T slots at low throttle openings and the primary main jet for higher throttle openings. So you have to sort out if you are cruising on the PMJ or the T slot and tune on one at a time.
To that end, to tune for WOT after you have the T slots and PMJ sorted out you only change the secondary main jet OR the power valve channel restrictors. Once you have the cruise AFR ironed out you never touch the PMJ again.
If for some reason you need to fatten up WOT a bit you open up the PVCR on the primary side and add main jet on the secondary.
Again, cruising down the freeway at 70 you are on the booster (which is another way of saying you are on the PMJ) so yo would adjust that and get it correct.
And you have already cleaned up your transition and T slot AFR.
Once you have that sorted out you can go to tuning for WOT. If your cruise AFR is where it should be, you don't touch your T slot restrictors or the PMJ. You change WOT with your PVCR's and the SMJ.
This of course leads to unscrewing the power valve timing issue.
The power valve cold have been named the economizer valve because that's really what it does. It allows us to run a very lean and crisp, clean cruise on the PMJ and then as you get further into the throttle and vacuum starts dropping the power valve opens and adds extra fuel. It really is two small jets behind the power valve. They work like main jets but they only add fuel when manifold vacuum drops below whatever your power valve is rated at.
A 2.5 power valve will open significantly later than an 8.5 for example.
Holley says (and so do many others but they are wrong) to set your power valve opening point at half your idle vacuum. If you have 14 inches of vacuum at idle they'd say use a 6.5 to start. And that's probably not close.
I use about 75% of CRUISE vacuum to start with and tune from there. If you have 18 inches at a cruise then I'd start tuning with a 10.5 because that's all you can get in that range. If I could get a 12.5 I'd start with that.
The thing to remember about the power valve is it tunes two ways.
One is off manifold vacuum (when it opens and shuts as the vacuum goes up and down with load and RPM) and the other is with the restrictors.
The rating (8.5 or 4.5 etc.) sets at what manifold vacuum it opens (which is really the start point that it adds fuel) and those little restrictors control how much fuel you are adding. And any change you make to the PV is always separate from the primary main jet. You can change the opening point (which will add fuel sooner or later) and then change how much fuel you are adding at WOT.
You can find some nice little power gains but more importantly you can trim the fuel curve right up and get EFI like fuel consumption and drivability if you learn to tune.
I hope this makes some sense.