Believe it or don't but I just went through the exact problem with My 472 Hemi I changed carb..new fuel filter..new high flow fuel pump...cleaned all the paint off the orange box and fender to get a better ground..none fixed it. A friend told Me to check the alternator as He said it might not be putting out enough at low rpm. I checked the alt and it was good but noticed the belt was not as tight as it should be. I tightened the belt and have no stalling at idle any more. And that's the truth.
I am glad you found a solution
But electrically, it does not make sense. If the alternator output was low, the battery should have supplied adequate current/ voltage to compensate for the low alternator output. The exception being the battery is very weak or there is a problem elsewhere in the circuit. In that case the Alternator could back feed the circuit to mask the root cause
I worked this issue along with an established Mopar Guy of over 50 years,( his time of experience, not how long I worked the problem,lol) even He said He learns something every day. The car would not stall when warming up...take it out on the road immediately after startup and it ran normal. Once warmed up at operating temp, it would idle at a light for a short time and stall if too long waiting. IF put in neutral and run at high idle,1300rpm, it would not stall. So after tightening the belt I "assume" it was slipping at low idle enough to drop voltage at the box. It would not stall when warming up as it had a higher idle speed while warming up. Makes sense or not, I have had the car out several times and it runs and idles great.
