I've got a like new jack base with a stamp of U69 i'm guessing 1969 what does the u mean (week)? how do you date the base/jack/ hook ect.

Dec 69
A = Jan
M = Dec
I = Not used

Well without seeing a picture of the base I think you could be the proud owner of a Chevy Base. Dont take my work on it do an Ebay search for Chevy Jacks or Camaro Jacks and see it something comes up that looks identical.

Here are a couple of pictures of jack bases.

Solid T-Mast

Tube Type Mast

All U69 Jack Bases on E Bay at the present time are for 1969 Camaros. Item Number 120371723100 is one example.

Snoopy your post with the T Type Jack Base I believe is for a 70 or 71 E Body with a T Type Mask.I am thinking that your U70 Base might be for a 1970 GM. I have a U69 Jack base and it goes with the 1969 Camaro Jack Assy I have.

The one on the left is Mopar, the one on the right may be GM. Both are U70.

Well heres the U69 base, looks different than ones on e-bay got a notch on the side, probably for Yenkos, .

The jack in my 71 demon is stamped 2K my rear bumper has notches? shaft does not fit into base,hole in base is bigger so my jack is not safe to use, so i'm guessing i need a base with A,B,C 71 to be correct for my 4/71 built demon.