turns out a bosch 5 is same heat range as an ngk 7 anyway.......they are those super4s multi electrode jobbies though so a change is still on the cards just ordered a dial gauge too i shall move belt 1 or 2 teeth and then mark a new zero on vernier for equal split on 4 before going on the rollers to play with advance or retard from this point as will only need an hour then thanks all
