i changed the spark plugs on my 70 elcamino (ss396 clone) the other day. as i pulled the old ones out i tagged which cylinder they came from. when i was done i inspected each of them and they did not all look the same when i compared the spark gap and electrode areas.

2 looked slightly brown, 4 of them were a bit more dark (slightly carboned up) and the other 2 were more heavily carboned up.

is this normal? i thought they would all look about the same?

the engine is bone stock except for an HMI transplant and an 750 edlebrock carb. they are gapped at 45. it normally idles slightly rough when cold and smooths out when warm, and runs pretty good.

is this normal? :confused:

Each spark plug that I have ever removed has been different than any other one. Its like the old saying, no two snow flakes are the same. Different cylinders might wear differently causing oil to possibly burn in one cylinder and not the others. I read your other post about the smell in your oil. This problem with the oil and spark plugs could be the same result of a problem with the engine. Do you notice any smoking or burning of oil out of the exhaust? How many miles are on the engine and has it been rebuilt? Just a few ideas that might be a possible help to ya.

thanks for your reply. good info.
the engine has been rebuilt by the previous owner. he swapped the heads, so now it burns unleaded gas. not sure when he did it. odometer says 85k, but i don't know if that is acurate or if it has turned over.
i have never seen any smoke from the tail pipe (besides condensation when it is cool outside) and it doesn't seem to burn any oil within the 1,500 miles i drive it during the summer.
sounds like the plug differenaces is normal. - thanks for your help