first i have a 250 w/ a holley 390 carb, langdon's dual exhaust to 2" pipes, offenhauser intake is heater w/ water. ok
while doin a little tune up and oil change today i noticed the the middle two plugs were black, outside of them were white, and the front and back plug were brown, i'm assuming this is from the fuel (holley 390 carburator) going more to the middle cylinders
but my questions are 1. is this a major problem, will it affect performance and 2. what could i do to improve.
