Get that annular, put it back to factory settings, screw it down to the big block, put some tape over the AFR gauge and go for a drive. Just go for a good drive taking mental notes on drivability. THEN take the tape off the gauge and observe. Too rich or lean everywhere then adjust mj’s and repeat first step. When MJ is in the ballpark then start looking at what bleeds may need tweaking to improve the curve.
Why am I telling you this? Because I went through the same with an annular of the same size but brand ‘D’. I read all of those threads too and was convinced there was too much emulsion, mab etc, etc. I was a slave to what the AFR gauge was telling me in conflict to what my butt meter was telling me with each change. I narrowed the tune down to
MJ pri 76 sec 85
Mab .025”
Iab .071”
IFR .033”
Emulsion .025” X .020” X X
PVCR .059”
Squirt .035” pri/sec
blue cam pri orange sec
Pv 8.5
(The above and all below have .028” kill bleed)
Gauge readings were nice and steady and where ‘I’ wanted them to be.
Put it on a chassis dyno to confirm WOT AFR. Dyno operator said he didn’t have to touch a thing, great job and only changed me half price.
I then moved onto another carb to tune. Exact same carb dimensions but downleg. My plan was to tune both these carbs like the forums say and then hit the track to see what will be the best performer down the 1/4. This is a Street/Strip car like yourself.
I start with lowering the IFR on the downleg and doing some light throttle cruising to size the lower IFR in the ballpark. One step at a time scenario. All the while the .031” X .031” X .031” emulsion as factory and .031” mab were in there.
I had the main jetting in the ballpark. Went for a few drives like that and gave it a boot full a few times. I thought the AFR could look better like the annular so followed the recipe so often espoused of mab .028” and emulsion of .028” X .028” X X.
AFR certainly cleaned up. I wasn’t convinced it performed any better but the gauge told me it was better. Nice, reasonably flat and steady AFR readings. It was accomplished by
MJ pri 80 sec 89
Mab .028”
Iab .070”
IFR .031”
Emulsion .028” X .028” X X
PVCR .063”
Squirt 35 Pri/sec
Cam blue pri pink sec
Pv 8.5
I was happy because the gauge readings were happy.
I then moved onto a 750cfm downleg of the same brand and type. This was mostly due to needing something to do during so much time at home with covid lockdowns to varying degrees. The 750 ended up the same as the 850 downleg above except main jetting and pvcr. I was curious as to what it would be like if it did have a similar calibration to those Holley HP’s and XP’s that get a hard time, just for curiosities sake. So I upped the mab to 33 and added a bottom emulsion for a .028” X .028” X .028” stack. Well, one thing that was undeniable is throttle response was improved and it only needed .031” squirt and pink cams. I left the bottom e-bleed in but returned to .028” mostly because I had it in my head “33 is too big!”.
Next was a Race Demon I managed to get my hands on with a few different sized sleeves. I liked the thought of the gold 1.500” venturi sleeves. Boosters are downleg. While going through the tuning of that and questioning whether x2 or x3 emulsion is the way to go I got some good advice from a knowledgeable guy on this forum to put an over sized mab in (.050”) and then test different emulsion stacks observing AFR curve. When the combination is found that is suitable then begin trialing mab to find what size stabilizes afr best or takes the ‘chop’ out. Something absolutely undeniable is that when I had the .050” mab in there the bigger I went on emulsion the better the engine performed, especially response to throttle angle changes. For the curve I settled on emulsion of .031” X .028” X .025”. MAB .033”. It only needs squirt of .031” and pink cams both ends. This carb is dynamite and is certainly going down the quarter when it re-opens.
Because the AFR darling was the annular it was put back on for street duties. What a dud compared to the gold sleeve downleg Demon! I thought stuff it, I’m going up in mab on this sucker! As I noticed as I went up step by step on the Race Demon from .028” performance improved. Went up to .031” and then .033” on the annular and sure enough the car felt better. I then went the whole hog and replicated the same emulsion as the 975 (gold sleeve) in the annular. That woke things up!! With a little more tweaking of jets and bleeds the AFR in general is close to where it was with all the tiny bleeds but just a little more erratic on the gauge but I will take that any day for the far better performance it gives me in my Street/Strip car. Done the same with the 850 downleg and hey presto! made the previous old school type calibration seem like an old man with a walking frame.
After my life story
from what I have observed is if you want to satisfy AFR readings then old school Holley calibration is the way to go, can’t deny that. All the theory of continuity of mains delivery etc is solid in practice. If you want the best performance out of your street/strip vehicle then don’t be afraid to experiment with larger emulsion and mab. You can arrive at similar AFR but what becomes clear is an AFR number alone does not always equal the same result. Same AFR number with fuel delivered to the cylinder in a different state = different outcome. It seems to me Holley, Quickfuel etc aren’t stupid with their high performance calibrations, they just need a little fine tuning to the individual application. You go to OE calibrations for engines far from OE specs and you may well be short changing that engine of its potential.
I know there will be some picking apart what I have said above but having trialed all of them there is no way you could convince me old school calibration is better than the newer in the high performance stakes.