Classic/Antique Car Repair: stalls or runs rough in drive idling, holley 4bbl carb, vacuum leaks

Question
QUESTION: I have a 1956 Ford Fairlane.Rebuilt the motor over the winter.Reinstalled with the original Fordomatic transmission.Starts great,runs fine in neutral.Lots of power and drives fine ONCE it is past idling in drive.Idling at 750 in neutral.Vacuum gauge 18-19 and rock steady.Drop into drive and RPM goes down to the point it quits.If it runs by increasing idle speed vacuum is 14 steady.I have looked at everything I can think of.New plugs,high output coil,carb float level and blown out all passages.Idle mixture screws working correctly.Reset valve clearance 3 times.In drive idling takes several turns of idle speed screw to raise rpm and then its excessively fast in neutral.A suggestion was made that there may be a problem with the torque converter.I did clean it up with varsol and pressure washer and I dont think water got in it but maybe?Sat all winter empty.The motor is stock with a  replacement holley 4bbl carb which works fine.no vacuum leaks.I am pulling my hair out trying to find the problem.Any suggestions and COULD the converter be the problem.RPM drops as soon as its put in drive.Thank you! Mark

ANSWER: Is it a 272, 292, or a 312? Are the valves set at 019" hot with the engine running? Does the distributor have a dual or single vacuum chamber?
Let me know and we will go from there.
Brad

---------- FOLLOW-UP ----------

QUESTION: Hi Brad1 I just sent some more relevant info if you check your questions.Sent 5 minutes ago.It is a 292 and the valves are set at.019.The distributor is the later 57+ type with vacuum and centrifugal advance.It is working correctly.I really think the problem may well be in the torque converter or transmission.Sent you more info as I said.Thanks Mark

Answer
The one way clutch is supposed to be in the lock up position during low engine speed and the release at higher engine speed and cruise conditions. Unless there is something binding in the converter between the impeller and the turbine, I cannot see where the converter is at fault. So, let me ask a few more questions. Where the valves adjusted with the engine hot and running? it makes a difference. I was a Ford factory instructor during the 50's and 60's. Is the vacuum advance seeing vacuum during idle? On this distributor set up it should not see vacuum at idle. It should see ported vacuum that does not come in till about 900 RPM. Are you adjusting the timing with the vacuum line disconnected? And are you adjusting the timing at about 500 RPM? That distributor if properly adjusted will start its advance curve around 700 engine RPM's. So, if you are adjusting the timing at 700 or so RPM's you could in effect be running a slightly retarded timing. In my experiences over the years the 272 and 292 stock engines did not like 4 barrel carburetors.
Keep me posted.
Brad