Runs then dies

I much apologize for the omission. It is a 4-speed.
Quite a bit of technical advice offered on the forum is beyond my limited knowledge or understanding. Therefore I get pretty hesitant to mess with carburetors other than simple stuff. Nut and bolt approach I am not bad at.
Today— With idle at 800 rpm- Reset timing to 20’ , it is 37’ with mechanical added, vacuum advance disconnected and capped. From cold start (73’) It died in 12 minutes with a full fuel filter. Was able to restart immediately (easily) and ran for 6 1/2 minutes before starting to stumble lightly and died in 10 1/2 minutes.
For my own knowledge, would not my 115# compression be equal to 130# at sea level ?