Carter AVS jetting for altitude

[femtnmax]

I have been running a 1969 Carter AVS 4640SA on my 440.  I list here the factory specs, and what I ended up with for best performance at my altitude of 5200 feet.
Original parts: Primary jet .101 inch diameter, secondary .095, three step metering rod .065/.060/.053.
Float setting 7/32 inch, float drop 1/2 inch, secondary air door spring tension 2 turns, accel pump to airhorn 7/16.
Accel nozzle diameters .035, idle jet inlet (part of the primary venturi) .033 inch diameter.

My final specs using O2 air fuel ratio monitor:  Primary .094, secondary .098, two step rod 6847, orange metering rod spring, underside of metering rod covers epoxied flat.  Float setting 7/32 inch, float drop 5/8 inch, secondary air door spring 2 turns, Accel link in top hole, accel pump to airhorn 7/16 inch, Accel nozzles increased to .040, idle jet diameters increased to .035 inch.
Idle mix screws turned out 1 1/2 turns, Idle speed with "square" transfer slot showing was 800-850 rpm with 9 degrees initial timing.  Have iron 906 heads and the engine struggles to hot start with more initial timing than that.

Off idle lean stumbling was cured by increasing the idle jet diameters. On the underside of the primary venturis there are two brass tubes, the large one with holes down the side is for the main metering system and the smaller tubes are the idle jets that feed fuel to the idle circuits.  I finally read somewhere about increasing the jet opening diameter and that was the key to a smoother running engine prior to the activation of the main metering system (off idle cruise).

Also really helped to eliminate the mechanical fuel pump.  I tried Mopar vapor separator, one inch carb spacer, and blocked off heated intake manifold cross-over.  Now using Mallory 4110 external electric fuel pump, rated at 110 gph and 7 psi with internal pressure relief.  This pump has been working well so far, several thousand miles on it.
Hope this helps.