1) Will not fit C-27s with hull numbers in the following ranges: 1421-1450, 2465-2549, 3101-3150, 3950-3999, 4701-4725, 5042-5051, and 5140-5149. These boats were not built in California and used a different mast. There may be other ranges as well that we have not discovered yet.
2) Although machined with a groove large enough to fit 3/16" wire, the 2" O.D. is too small for us to recommend this sheave for any wire larger than 1/8" 7X19. If used with a larger diameter wire, the small diameter of the sheave will tend to kink the wire as the wire rolls over the sheave.