'71 Challenger

Combo:

Stock Magnum 5.9
RPM Airgap Magnum Carb intake.
QuickFuel Slayer 600 VS Carb

Carb settings:

Mains: from 68 to 70's
Secondaries: from 73's to 71's
PV: 6.5
Pump Cam: from Pink, hole 1 to Orange, hole 1
Pump adjustment: seems to have a TINY lag. may need more preload
Squirter: 31
IFR: from .031 to .028
IAB: Primary from 78 to 84, Secondary from 37 to 43
Idle screws: 3/8 turns out
Transfer slot: "square" visible from underneath when primaries are closed

Behavior:

Idle AFR in gear: 12:1
Screws will kill it if both in, but seem to have little actual effect on A/F beyond 3/8 open. Cannot get AF to 13+ at idle
Cruise (maybe 10% throttle at 60 mph w/ 2.76's, 2000 rpm): 14:1
Very gentle acceleration, 15 - 16:1, surging, missing
Moderate accel: Lean spike (18:1 +) on tip-in, hesitation, sustained bog, then wakes up once the secondaries open.
Accel hard enough to engage PV: 12:1, but not happy until secondaries open
WOT: from idle will bog terrible, 10.8:1 - 12:1 after the secondaries open. It feels good past about 3000, but would probably be better if I could get it closer to 12.5 or 12.8.

I'm trying to get the idle mix screws to have an effect and be set around 1-2 turns out.
I am thinking the secondary metering plate is adding too much fuel at idle and I have tried to compensate by over-leaning the primary side, causing the lean cruise to be lean even with a fattened main jet. I may need to return the primary IFR to .031 and increase the secondary IAB's more to balance it out some. Once RPMs come up I get tons of fuel from everywhere, which is what caused me to lean out the secondaries. My tail pipe is VERY sooty. The car cruises at constant RPM at 14:1 just fine, but will NOT behave when accelerating at any rate unless in the low 12's and really likes the secondaries open.

i would start with putting something like a 9.5 power valve in it...

This car idles at 20" vacuum.

Stock is a 6.5. I put a 10.5 in and it would dump mass fuel in too early and easy. I could drop the PVCR's a few sizes to reduce it's effect and go to a 9.5.

Initial timing?

If it's not around 15-20, the idle numbers will be low as you have now.

16° and 36° by 2800. No pinging on 87 octane, but I do get occasional run-on. How does less timing cause rich AF readings? Is it "Actual" or "Indicated in error"?

You might bump the initial up (I got 19 on a bone stock 318 & could take more) which'll bump the idle speed up then reduce the throttle blade opening to lower the idle back to where it was & this will end result give less throttle opening will likely help with the run on. EDIT & as you know the mech will need to be shortened back (the $25 FBO plate is a hell of a deal)

Why do you have it idling on the transition circuit ?
Fix that, no transition slot expose with the idle speed screw and idle mixture screws set so it idles at 800 to 1000 RPM in neutral and 600 to 800 RPM idling in gear, your choice on the idle speeds
Way to many people on here have bought on and spread the bad internet myth that you must have the transition slot exposed under the throttle plates on every Holley type carb. at idle, bad deal
Fix that and try again on all the carb and ignition tuning and let us know YOUR results

Why do you think its an internet myth?
Mike Urich, Vice President of Engineering at Holley, explained the importance of adjusting the correct amount of transition slot exposure in Holley Manifolds and Carburetors. That books came out years before the internet. (first edition 1972, revised edition 1987). I agree that square is not a magic number, but 0 will produce a delay.

This link will self destruct in time. (don't ask me why. I just know it will happen).
T Throttle/transfer slot relation

Here's my take; On 4150's it's always necessary to have t-slot exposure on the primary and according to the rest of the motors combo, maybe even the secondary on big duration cams to get some extra needed fuel. Now Dommy's are a whole different animal at least for me and I never want any exposed if possible and my new builds don't usually and if so sometimes bypass air is needed then holes in the blades or in the main body's help there but can still be a bear to tune...........Most Dommy's will have the blades just barely above the top of the t-slots and in MOST cases are a breeze to tune and size the ifr's, t-slots,idle bleeds and mixture screw setting for a clean transition up onto the boosters............Your results may vary and every combo is different so a too small of a carb(common)on a bigger healthy motor are harder to tune than a bigger carb(hard to do imo)on a motor w/less cubes and power because of the sensitivity on the boosters w/the bigger cubes/more power. I've read the opposite on some forums but for ME this is how I approach and tune in a basic general way for starters............

UPDATE:

To get drivability back, I reverted almost back to stock.

-Primary mains back to 68
-Primary IAB back to 73
-Idle screws at 1-out

-PV dropped to from 6.5 to 10.5 (only one I have, will get a 9.5)
-added a .013 copper wire to the PVCR's to remove some of the excessive fuel added by the PV.
-Squirter was bumped up to a 35 from 31.

Most of the bog on tip-in is gone, such as when leaving a stoplight normally. It drives a ton better, but I still have the flat spot if I transition quickly from idle to ≈50% throttle, it jumps just a tiny bit, then just bogs and stays bogging, even though AF swings from 16:1 down to 11:1. Secondaries opening clears it out and it takes off.

Driving in this morning, I was at cruise, 14.5:1, pulling 13" vacuum at 2600 rpm (about 85 mph). At least SOMEWHERE on this carb is happy.

I'll reset the idle tune using the vacuum gauge this evening.

What sizes and how many emulsion holes in what locations.........

emulsion holes are not changeable in the slayer's metering block.

PVCRs, IFR, IAB, HSAB, jets, and Power Valve.

i'd guess the slayer has 3 emulsion holes per side, that's what the HR650 i have on my 318 is.
i think they are .031"..kinda large. but actually that carb (it's a 4150 though) runs great on a basically 318 stock motor, but it's a w200 and therfore 410 gears, 32" tires though is prob equivalent to a pass car with 3.55 gears.
i dropped the IFR's to .028" which is actually a little too lean but other than that it's all box stock and runs fine.

i wonder if the vacuum secondary is just a harder carb to tune..

I never recommend or use VS carbs on anything so not much help here............Muscle car = DP in my world and get just fine mileage and power w/out relying on a vacuum source for sec. actuation.......