What they said PLUS....
In this heat it would be my guess that you went up too many jet sizes since it didnt repsond, no matter what the plugs look like.
I'd go back down 2 maybe 3 jet sizes from the current 94's and give it another go with the 40 degrees timing and see if it hauls the mail, I'd do that before I went out and bought another carb, but thats..... JMO>Cp