I'm almost sure the lower control arm are dfferent from 1973 to 1976 and the arlier ones, the hole for the lower ball joint stud is different. [/quote]

That is not true.
You are misinformed about that, for some reason or another.
Ball joint stud hole diameters are all the same throughout all the years.
Nothing at all changed in the LCA's. [/quote]
I agree as I pulled a good bit of uppers to get older disk brakes a a ton of 1973 up.
It is the uppers that are diff.