Off the top of my head, there are quite a few. These are different in obvious ways(grooves or not, bolts or pins, different stamps). I am unsure of any inletting differences/lightening cuts/holes. Please let me know if I am missing anything or made errors(likely). These a kinda in chronological order, but not necessarily. Keep in mind, there are always transition/overlap periods.
1)Grasping Grooves, RLB in a box, bolts
2)No Grasping Grooves(from here on out), RLB in a box, bolts
3)RLB no box, bolts
4)Spread R L B, bolts
5)FJA in a box, bolts, no A3 ring relief
6)FJA no box, bolts, no A3 ring relief
7)FJA in a box, pins, no A3 ring relief
8)FJA no box, pins, no A3 ring relief
9)FJA in a box, bolts, A3 ring relief
10)FJA no box, bolts, A3 ring relief
11)FJA in a box, pins, A3 ring relief
12)FJA no box, pins, A3 ring relief
Gets kinda confusing at the end of production. I think there are a couple or few that don't even exist. What do you guys think?
Mike