Hello Todd. Sorry for the delayed response. I ended up having to travel out of the country so didn't have a chance to touch base. I checked and I need the 13/16 version so unfortunately I don't think this one will work for my situation. But if I change my mind I will let you know. Likewise, if you find a '68 w/ 13/16 drive please let me know. My email is greg.patterson@porticos.net. Thank you. Greg P.