take the carb apart and take a look at the jets and every other possible area where fuel flows. I have heard that SOMETIMES small pieces of metal caught in there after production.
AND, if you take the time to READ each thread, you will see that NO ONE said you put a torch on your carb. Let me sum that portion up: I suggested that you do it to help loosen the air cleaner stud. And someone else said to NOT do it unless the carb was off your car and cleaned. To which I responded: I thought that was a given.
Now, have you tried the PB BLASTER for a day and then the vice grips? Another option is...if you know someone that has a welder, you could screw a nut on there and then have them tack it on there...again you run into the fuel issue though. Once the Nut is tacked, you have something that your socket can grip on.