I have been chasing the causes of not so smooth idle on my VP 4.3gxi. Found out that even though all 6 plugs are the same Acdelco 41-993 then somehow on the port side all center electrodes look different then those on the stb side. Made also a picture of it, and only when at home looking at the photo discovered there are numbers that don't match either - on 3 pcs it reads ...6067 and the other 3 it reads 7234. Could this be the reason of unclear vibrations and shaky idle specially in the cold startup? And, if I now buy new ones which ones they should be?
