Rear End Code (think its from a '75)

[John Rohe]

Hello folks,

I'm a "brand new" member here (no # yet, I just called in my membership on Tuesday). I've got a '67 that I'm sure does not have the original rear in it. The stamped in codes read as follows "AOW 347 E1", and the casting date on the driver's side is "L 6 4".

At first I thought this was a '64 casting, but someone told me that the julian dating of rears didn't start until '71, which would mean this is a '75 rear with a casting date of December 6, 1974 and a build date of December 13, 1974 (347/365). My question revolves around the AOW coding. I know that AO is a 3:70 ratio for earlier cars, but I can't find the AOW code listed for a '75 application in the sources I have. Any help would be appreciated.

Thanks, John R.

[Tony H.]

Re: Rear End Code (think its from a '75)

The AO is for 1965-69 (early). The W represents the Warren plant. 347 is the Julian date and the E is for the positraction source, Eaton. The 1 is the shift. My guess is it is a 1965 gear based on the given information with a casting date of Dec 6, 1964 and build date of Dec 13, 1964.

Now if the O is really a C, then it is a 4.11:1 ratio and the rest of your information fits for 1975.

I don't know when Julian dating of rears started. Maybe someone else with more knowledge can help us with this puzzle.

[John Rohe]

Re: Rear End Code (think its from a '75)

Tony,

I am positive that the stamped-in coding is AOW. To the best of my knowledge '65 rears would have used a date stamping such as 12 13 65 for December 13, 1965.

I'm not 100% sure that Julian dating wasn't used in '65, but I don't think it was. Back to my original question, does anyone know how to decode my rear?

John R.