Hi,
I have a Model T Coupe hot rod that appears to have an Oldsmobile or Pontiac rear. I think its 40's 0r 50's. A friend said it is dated as 11/4/57. thinking maybe 47 so since late month, a 48 or a 58 rear but ?? . I just cant find another picture that has certain things such as the square boss above the date code, near top right rib and there is a fill plug on backside which I dont see anywhere. Also backing plates for brakes have a partial outer lip, not full lip all the way around. Can anyone help me? I want to do bearings, seals, brakes etc....
Thank You,

 

Is there another number ( 6 digits ) on the housing?
It sort of looks like a 57 thru 64 rear, but that number would tell us for sure.
That number you show is a date code and decodes as follows.
K== October
4= 4th day
7= year , could be 1937 or 1947 or 1957

Is it a posi?
If it is, then It's a 1958

 

K is Nov right? 11th letter. Not posi. Since nov of 47, would that be considered a 48 since Im assuming it went into 48's. I have no idea, just asking. Also I believe 47/48 is only years of fill plug on back, 48's, not sure of 47's but if code is def considered 47 then both. Wondering about brake backing plates as well. Mine have the flash lip over the top part of the backing plate and not all the way around like most. I've seen it on 51s as far as pictures but I don't know about these years. I'm wondering if it's correct or if somebody used later model backing plates. Any insight would be much appreciated. I'm just trying to do brakes, wheel cylinders and axle seals possible bearings. Thank you

 

Did you find another number cast into the diff carrier , besides the one you posted?
That number will tell us exactly what it is.

 

I am out of town until 2/7. I will get other #'s etc when I get back. Thank uou very much, appreciate it.

 

Need better pictures and an axle spline count would help a ton.. Pinion yoke area... it is not a 1957 Olds or Pontiac. casting just does not look like that...I have plenty of them to reference...The casting fins are just wrong...BUT it is close so that is why it might be a 1947 ...BUT I do not even have a CLUE what a 1947 olds rear looks like at all . The yoke will help ID the era a bit. 1957-1964 Olds will have a full 1/2 saddle for the u joint to sit in. The older 56 and older the saddles are shallow and not very good as the u bolts are the only thing that really hold it stable back them...Just technology and design got better because the vehicle were getting more and more power.
Backing plates are really old type they have not 90 degree outside diameter ledge for the drum to seal out the elements. They are just flat again putting it in the 1955 and older era.
OLDS Pontiac 1947 ?