Hi Dave, Excellent suggestion that anyone modifying their driveshaft perform the work on another, non-original driveshaft , and not on their original and correct unit ! I have added a caption on the Web page with the pictures to that effect. ! I am not sure what year 300's used special, thicker diameter driveshafts - I know this is true of 60, 61 and 62 at least. But there are plenty of Windsor, Newport and NewYorker parts cars in junkyards that a used driveshaft can be obtained from ... play it safe, and chop up one of those if chop you must ! John