Need help tuning Quickfuel carb

Isn't 2500 about where the MSD switches from multi-spark to single strike?
Does that carb have a 4-corner idle system? Yeah I think it does.
Hang on,
You said that was a 380 hp 360cid right? That should have a 288/292 cam and a singleplane on it.
Idle vacuum of 20/15 with 288/292cam, and a single plain?! That don't sound right to me , even with what seems to me, an excessively fast timing curve,unless maybe you are idling it quite fast.
And your problem is mostly or all at part throttle right?
and you said your timing was 18/34 all in at 2500 right?
Are you also running a Vacuum advance, and if yes, then how much is it kicking in?
At 2500 and briskly loaded (as in accelerating briskly) that engine might like 40/42 degrees PT (Part Throttle) timing and not much more. Since your mechanical is 34, this would allow only 6 or 8 from the can. I would disconnect the Vcan and retest.
That engine may want over 50/55* of cruise timing. That would require a Vcan of 20/22* to go with that 34 mechanical.
But if you combine the 22 can with the 34 at 2500, you would be jamming the engine with 54*2500 at PT , and guess how the engine complains about that?
I think, If you have an operational Vcan, that you have more than one problem. So again, I recommend to disconnect the can and retest.

Then, Ima thinking your T-port is off and your secondaries are cracked open too far. And just maybe the butterflies are staggered; that is to say the left and right secondary airvalves do not both park closed at the same time, or, one of the secondary mixture screw circuits has issues..

But I'm guessing,lol

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FYI
As to PVs;I run an 8.5 with 11" idle vacuum................. because my street engine told me that's what it wanted. This is real easy to see if you pull it out and sub in a plug; then go for a ride with a vacuum gauge.
But I run a one size smaller than normal MJ, cuz it's a streeter,so the PV has to come in a lil early to cover the hole.This allows me to run a little leaner on cruise/PT. And to cover that, I run a lotta lotta cruise-timing; Up to 60*at one time, and a lotta quench; .034, and a lotta cylinder pressure.