Lead

Are ther additives out there to Help this 1956 f-100 pick ip run with knocking. Any help would be appreciated

Well you won't find any leaded gasoline because of the EPA. Is it detonation or is it worn out? The main thing the switch from leaded to unleaded gasoline affected were the valve seats. Leaded gasoline helped cushion the valves when they closed. When you use unleaded gasoline, there is no cushion and those old seats would get pounded into the head. I'm assuming it isn't a race engine so have you checked timing? Is the combustion chamber carboned up? Is the carbuerator adjusted properly?

Well you won't find any leaded gasoline because of the EPA. Is it detonation or is it worn out? The main thing the switch from leaded to unleaded gasoline affected were the valve seats. Leaded gasoline helped cushion the valves when they closed. When you use unleaded gasoline, there is no cushion and those old seats would get pounded into the head. I'm assuming it isn't a race engine so have you checked timing? Is the combustion chamber carboned up? Is the carbuerator adjusted properly?Seafoam YouTube - The Official "How To Use Sea Foam" from Sea Foam and GUY. (http://www.youtube.com/watch?v=D11ZVYwj62w&feature=related) Also, as mentioned, are you running lean? How old are your jets? Running rich will also eventually end up pinging. Running a higher octane may help temporarily, but will soon replace combustion chamber deposits. I'd try the seafoam to begin with. This may help illiminate contamination deposits as the "in your face" problem.