i had this same problem with my 65 comet when i first got it. it drove fine for 300 miles and then out of the blue... i got the herrkey-jerkys (it is what i call it) in my case , i started my car up it would run for 15 minutes and it would cut on and off...on and off... and stall out. i got too the side of the road and waited for the motor too cool down and nurse it home. i did the same thing.. got a new carb,filter,protronix,and went in the tank, even blew out the gas line(tank too pump). i gone through three mechanics . they all told me too leave them alone . i had a spare fuel pump,no hope,and all the time in the world. i changed it myself and 3,500 miles later i still have no herrkey-jerkys. it may or may not work , but you got all the time in the world! don't get upset ... get inspired!