Yay or nay??? I have a set leftover from my M50, want to know if they are ok for the ol' M40B18, it's the sohc. The nomenclature used on the board is at times a bit confusing. I naturally assume that 'M40' refers to the (later)sohc 1.6/1.8l, and the 'M42' is of course the dohc.