Re: [Chevelle-List] spark plug

[SUPRSPRT72]

Hi Keith,
depending on the condition of your old plugs, try checking the gap from them and see where abouts it is,  from an average of a few of them,  if the car was running or running good with the gap you were using  (or if you have them at all) then there yago
Ken D. 72 HeavyChevy