Want to put new pistons in my panhead. Made a ring fixture to mount in a 4 jaw chuck. OD and ID run true, has 4 holes in the face to mount the cylinder. Trued the ID in the lathe and made the hole a slip-fit for the sleeve end for the jug. Faced the fixture so the cylinder base would run true to the bore. I mounted the first cylinder and indicated near the top of the bore, and it runs out .008". Ran the indicator down the bore and it's good within .002" in 3 or 4 spots. The bore is stock (3.4385"). Is this something anyone has seen? I thought the bore would run truer than that provided the face of the fixture was true to the axis of the lathe.