Topic: shackle stud diameter

[67gta289]

My original shackles (C6OE) are being messaged to remove pits, and I'm looking for a better set also.  Picked up a set on eBay and, while nice, they have a 9/16" diameter stud instead of like mine at 1/2".  The stamped ends are dead ringers. Did I get a 69/70 or later version? 

Anyone have a decent used set they are willing to sell? Thanks, John