<VV> Starting 4 year Dormant Car

[Smitty]

Smitty Says;   An elderly clubbie that lives 65 miles away has asked me to get his car running so he can sell it.  I want to be a nice guy but the fun is gone after 3 round trips to get it going.  I’d like to have some suggestions or thoughts I can follow up on.
60 model with very good engine.  Good compression , Good valves.  Carbs have been cleaned and rebuilt and even swapped out for other rebuilt carbs.  Fuel pressure is up to 7 psi for the short times it is running.  It will start and run for 3-4 seconds and then die.  Not even long enough to use up the fuel in the bowls.  This can be repeated any time.  Fuel is being supplied by a outboard motor gas tank with priming bulb.  Other times  I have used a lawnmower fill can sitting in front of the engine lid.  Plenty of gravity).  I Don’t know if I trust the accuracy of the fuel gage all that much but the bowls are filling rapidly and and the float valves are handling the pressure OK.  The proven good fuel pump was replaced with another known good pump  During trouble shooting the distributor was found to be in lousy condition.  Flyweight springs were loose and timing was flopping all over the place.  The springs were replaced. Points were making electrical contact most of the time.  gg.   Corrosion on faces.  Those were replaced  Internal plate ground wire was broken.  Timing is set at 4 degrees as per the book.  Vac advance is stroking like it should.  I didn’t expect those things to fix the problem and they did improve it while it was running but didn’t keep it from dying.
I am convinced the problem is fuel but due to the non changes with different carbs I will now believe anything.  Quite a bit of backfiring indicates a going lean condition as the engine dies.  This afternoon , grasping at straws, I changed the plugs which contributed nothing.   Come on guys, I need some answers.  I’m too damn old to be taking this kind of abuse.