GZP Cylinder Knucklehead rear, 61"

Cast iron alloy, stock displacement, standard replacement cylinders. When you order cylinders only, please note that these are bored and honed to close tolerances, however due to variations in piston sizes we advise to check piston to cylinder clearances. Alternatively, for 1948 and later models, we offer ready-to-install sets of honed to exact size front and rear cylinders with Genuine Zodiac pistons and Hastings rings for high trouble free mileage.