i have a 8 3/4 489 case with 8u31 date code

[mike ketterer]

trying to decode date code from my aar.  489 case. date  8u31.   gears have  9-16-69  3.55 ratio.  trying to see if they are original to my car.  my other aars dont have that kind of date on the case.

[6bblgt]

if those two have always been together, I'd say "8U31": 8 = August & 31 = 31st  (8/31/69) but that's a Sunday 

the ring gear date 9/16/69 is a Tuesday

anyone else have a 489 case out & can compare the two date, or have that date format on the center section?