I personally agree with the list on these additives, but... My Dad always would end up rotating some thin kind of additive (Marvel Mystery Oil-I think) and some thick honey type(STP). He did this whenever the lifters started to tick. His 440 is a '70, has 110,000 miles, still runs well and has never had the valve covers off. I doubt that fuel system cleaners will help clean a carb. Just spray it with Gumout to get it clean, then use some spray lube & change your fuel filters. Rob PS: You cannot argue with my Dad. He still washes the car with Ivory soap. _________________________________________________________________ Chat with friends online, try MSN Messenger: http://messenger.msn.com