I hate to be cynical, but I think that the problem is not the additive, but your gas tank. It's probably filled with old crap and THAT is what gummed up the valves. Even if you put in way too much gas additive, or a quart of oil, it would make fluffy oil deposits, I doubt it would make that tarry crap that sticks valves, and it certainly wouldn't do it in a few miles. Unless you want to do this a third time, I think you should drop the tank, empty it, blow air into it with a shop vac until dry, then poke a rod in there to see if you have ANYTHING collected in, stuck on, the inside of the tank. The stuff in my tank that ruined a new head was dry and crumbly. You would never imagine that it would gum up valves. It looked and felt exactly like rust mixed with light clay, or something. But it partially dissolved in the gas, and melted into black tar -- on the INTAKE valves. It wasn't combustion, it was dissolved and the heat condensed it or something into tar. Check out the pics here.... http://wps.com/AMC/1963-Rambler-American/Gas-tank/ -- All your arguments are invalid. Enjoy your unstable system. _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list