Ok, I'm stumped. Need help with Id, upper control arm.

I've been around cars for at least 45 years and seen about everything. But I've got a couple NOS GM upper control arms that for the life of me I can't ID. I thought I'd use the vast knowledge and experience of the HAMB to help me.
Any help would be greatly appreciated. Thanks Keith.

 

are those the screw on METAL bushings and not rubber?48OLDS?Hell Im guessin!

 

It's got ball joints so it's probably mid '50's or later if it's GM.

 

bttt