help with exhaust manifold casting #'s

I have 2 sets of exhaust manifolds want to get info (Both came off 340 Dusters)

first set
3614368-2 date 10-14-71
3418623-2 date 12-21-71

second set

2863549 cant find a date
2863558 " " actually this is 2863553 sucks losing your eyes
Thanks