Does this happen when starting from cold, after driving 10+ miles, hot, or "all the time"? Putting it in gear as soon as it has started or letting it run a bit before starting off?
This IS an emissions-era motor, when many things were getting tried to get the engines to be in compliance with emissions standards. They were generally running as lean as they could, so modern-era (or even GM-style) cold start driveability can be an elusive goal.
BUT, there MIGHT be a few things you can do to make things better. Involving some tweaking of the automatic choke thermostat setting, some tweaking of the vac pull-off adjustment, idle speed while in fast idle mode, AND even some of the fine-wire electrode spark plugs. ALL using approx. factory base timing specs!!!
As for the base timing specs mentioned, are these mechanical-only numbers and is the vac advance hose hooked up to the distributor for ported vacuum?
When you advance the base timing on an engine with a carb designed for less timing, you generally get a faster base idle speed, which to maintain the normal base idle speed, you close down the idle blades more, which puts the throttle blade position below the transition ports on the carb base. Which CAN cause a hesitation off-idle as it takes more time for the main system to start flowing, which the accel pump can't cover that lean situation. NO matter which rear axle ratio is in the car OR how loose or tight the torque converter might be.
DO ensure the choke thermostat in the manifold is set to specs. IF it is the OEM item, then you might try going one notch lean, as with age, the springs tighten-up, so a slightly leaner setting is needed. The choke plate should just close easily at 70 degrees F ambient (engine, choke thermostat, air around the engine, everything . . . with the engine cold). Then with the engine stopped, compress the choke pull-off plunger and see how far it opens the choke plate. Use the "V-area" in the link to adjust, open for a bit richer and close for a bit leaner. On the fast idle cam/screw, back off the fast idle speed screw until the lowest step on the cam will clear (not touch) the screw, but will raise the idle sped on the 2nd from lowest step. Aim for the lowest step to increase the base idle speed by about 50rpm, if that much.
Set the base timing to factory OEM specs. Distributor vac advance hose unhooked and plugged.
Then make sure the hot base idle speed and mixture are adjusted to "lean best idle" orientations at the OEM-spec hot base idle speed. Probably in the neighborhood of 700rpm on that model?
Now, where do the fine-wire electrode spark plugs come it? NGK claims they will fire a leaner mixture easier. They also exposes more of the ignition spark to the fuel/air mixture, for a better "pow" combustion. A few YouTube videos on that in lawn mower engines. So they can help things along a bit, but not completely necessary, from my experiences BEFORE they came out.
The Holley 2245 2bbl does not have the Chrysler factory-fix "Bridge Kit" on it, so make sure the choke blade is not touching the air horn as it closes. Or has put a small shiny spot on it from repeated contact. PM me about this. Is the EGR valve OEM, too?
Are the carb and distributor OEM to the engine or have they been changed? Are the carb hold-down nuts snug on their studs?
I realize that at this time in the vehicle's life, seeking to get it to make as few emissions as it might have when right off the assembly line might be an onerous task, so just getting it to work its best is the main issue at hand. BUT also getting it to do it as the leanest orientation is generally best, from my experiences. Any little bit of richness should be just to get it past a particular time-frame in its various operational modes rather than "constant". But not so lean that it has "spit-backs" and such. By using some of the tweaks mentioned, I got our '72 Newport 400 2bbl to work better from a cold start, back when it was "a used car", with a similar Holley 2210 2bbl. And then later with a '70 383 spec Holley 2210 on our '66 Newport 383 2bbl.
Thoughts and experiences,
CBODY67