Note--that's for a single-point distributor, correct? Doesn't Petronix list a separate part number for the 351C/429/460 distributor with a dual-point setup?
If you try to fit that to a dual point dizzy there is a good chance that the magnets wont line up with the pickup in terms of height and you might not get a good signal as a result. . The dual point setup has the cam lower on the shaft IIRC.