Check for fuel by removing air cleaner and hitting the throttle and no fuel squirting from the jets, not even a trickle. And cap is correct. And when I removed the cap thinking it was a vaccum effect in the tank there was no whooshing sound so the tank is venting correctly. And the Pertronix is testing correctly and have spark at plugs when this is occuring. Changed out ignition due to the old prestolite icm was failing once it got hot and this is different on the stalling than that was. No back fireing when its trying to keep running as when the spark was failing. Just seems to be cutting out the fuel when vaccum raises from the idle speed. Can drive at slow speeds as long as I dont push on the accelerator to gain speed. Vaccum lines have also been replaced and routed.
Oh another thing. This is a Quadrajet carb if that helps any.

Thanks
Joker51