Set of 12 x chrome plated head nuts. Late KZ type (picture right) with height of 18.5mm. Unless you are fanatical about originality, I would use these on all models. Even better, the 72-342 billet head nut set. It’s really annoying to try and torque down the head and find that the dome nuts have bottomed out on the studs.
Models: 72-75 Z1, 76-80 Z900-1000