I installed the fuel pressure gauge in a way that would allow me to read it while driving. I found that pressure would drop to 0 psi. during accelleration. Then I started looking at fuel lines (again). I noticed that the rubber line going from the steel line to the pump looked a little flat. Once I replaced that hose the problem went away. I still can't believe a .50 cent hose could cause me so much grief. On a more positive note, my baby is running again, the odometer has at 1000 mi. less than it would had I solved the problem sooner, and I found the original build sheet when I dropped the tank, and it was still legible.  Thanks for all of of your input.

[QUOTE=DStoffel]No intake mods. Original Rochester Quadrajet. Had it rebuilt 2 years ago right after I removed what was left of the emission components (charcoal cannister and items related to the exhaust system). Car Was running great until last month.  At operating temp. I tried to maintain 2500 rpm while manually closing choke about 3/4 and it still stalled out after a minute or2. [/QUOTE]

My 1981 with the ECM and Q carb had almost the same symptoms.  Had the ECM replaced, did not fix problem.  Had the carb rebuilt.  She has been running great ever since.  I still have all original componants of the emmissions system.  She is stock, inside and out.