need help on Pinto 2.3

This is just a guess on my part, but any chance it could be vapor lock?

Wish I could be of more help, but the most I've ever done with a carbed engine is change the spark plugs on one...can't say I know much about carbs.

What does it do when it shuts off? Does it sputter and die, or just die with no warning?

Check float level.

If it has the Duraspark 2 electronic ignition, I suggest changing the pickup coil inside the distributor.

These are notorious for failing hot exactly like what you describe. If you can get it to fail in the driveway, check for spark when you crank it. If no spark, or poor spark, and you have changed the coil and duraspark box, try this.

It should be under the rotor and advance mechanism, and is the item the wires in the dist connect to. Should be $20 or so at a parts store.

I changed one once, and then put the old one under a halogen light on the garage floor with an ohm meter across it, and a thermometer next to it. It was fine cold, but when it got to 122 deg, it went to an open circuit like a switch was thrown.

Cooled down and came on again. Really annoying when its in the vehicle.