jack hook numbers

I have a 71 duster that looks dead stock original. It does not have slotted bumpers, the 70 duster has a wide bumper where the 67-9 are smaller??? Or depend whether dartor cuda??? Just wondering.
I have some NOT OEM hooks I can use on my cras and sell these IF someone wants to pay what I figure they are worth. I don't tend to be that correct a purist!!!!
Thanks for the info.
I have collected data for years from factory cars. Not completed yet!