Can you I.D This Rear end

The numbers are 2070742 then
the number 18 and then you can see the big #2
spring perch is 43" apart and the back plate's from the in side is 51"
I have not opened it up yet to find what gears ar in side.
I am hopping on finding a sure grip with 3.23 or 3.55.
This will be a long revamp , new studs and hubs,brakes and allot of elbow grease, But I am looking forward to getting this rear end looking and working buy spring.
Thanks for the help that I will figure may be hard to figure out, if at all.