I've had good experience with Chevron 'TECHRON"
After a long winters nap, my '53 was awakened to a nasty fuel delivery problem - terrible hesitation and rough idling. I was going to replace the carb with a spare but decided to use some Chevron Techron Concentrate Plus fuel additive/conditioner that I purchased from O'Reilly's first. The result was impressive as it resolved the problems.... I drove the car around for about 10-15 minutes and the carb cleared right up. Its been running fine ever since. I'm impressed with this stuff....