Have a 70 442 which has a SF posi 323 rear. Differential cover shows casting number of 402227 which matches to a 1970 Olds rear. This number shows on the inward side along with a clock type circle showing 12 dots. at the 7(july) it has 2 dots so I'm assuming built 2nd week of July. Is there a julian type date (letter with number of month produced). somewhere's on the differential. I can't find it anywhere's if it is.

 

No, there is no date code stamping on the rearend, just the axle code ratio on the passengers side tube.

 

Can you tell me if that clock that I referred to on the passenger inward side of hub of differential which shows 12 dots and at the 7th dot shows 2 dots. Does that actually mean a 2nd week of July production date?
Rob

 

There should be three numbers in that clock area. Those three numbers refer to the day of the year built.

 

Thanks for the info. My number is 261 so around Sept 20 or so. However, the clock still baffles me. Appears to show an arrow at 12 and then 12 dots with 2 dots at 7. So I assumed built 2nd week July.
Does that make sense or does this clock mean something else?. If so it conflicts with the 261 date of 1970. Case is correct casting number for 1970.

 

I believe the clock has to do with the time during the shift it was cast. The September date would be for 1969 when the production of the 70 models began. The number would be a lot lower for a 1970 year casting date.