Rear Differential date code
Thread Starter
Le Mans Master
Joined: Nov 2000
Posts: 6,266
Likes: 156
From: Galloway Twp. NJ
Cruise-In VII Veteran
Rear Differential date code
I'm trying to figure out what year this rear is from.. so far I know it's a 3:70 Posi (from the "AO" code and from turning the shafts) but I can't tell what year it was made.
here is the stamping from the bottom of the case.
AO W 265 E1
Thanks!
here is the stamping from the bottom of the case.
AO W 265 E1
Thanks!
Team Owner
Joined: Sep 2006
Posts: 31,109
Likes: 4,170
From: Westminster Maryland
Hi,
The info I'm looking at shows 'AO' was the code for a 3.70:1 sb differential in both 68 and 69.
The AO code was first used in 1965, so 2nd month, 6th day, 65.?
Regards,
Alan
The info I'm looking at shows 'AO' was the code for a 3.70:1 sb differential in both 68 and 69.
The AO code was first used in 1965, so 2nd month, 6th day, 65.?
Regards,
Alan
Last edited by Alan 71; Aug 2, 2012 at 02:55 PM.
Burning Brakes
Joined: Dec 2010
Posts: 848
Likes: 60
From: CA
AO was also used from 65 to 67 as well, so to narrow it down, you'll need to find the casting date on the housing. It should be in a format like C238 or similar. The first letter is the month, the second two numbers are the day of the month and the last is the year. In my example, C238 would be March 23rd, 1968.
Ed
Ed
Thread Starter
Le Mans Master
Joined: Nov 2000
Posts: 6,266
Likes: 156
From: Galloway Twp. NJ
Cruise-In VII Veteran
AO was also used from 65 to 67 as well, so to narrow it down, you'll need to find the casting date on the housing. It should be in a format like C238 or similar. The first letter is the month, the second two numbers are the day of the month and the last is the year. In my example, C238 would be March 23rd, 1968.
Ed
Ed
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Thread Starter
Le Mans Master
Joined: Nov 2000
Posts: 6,266
Likes: 156
From: Galloway Twp. NJ
Cruise-In VII Veteran
looks like a backwards "S" to me.... not an "8"
1 10 S ????
and the casting is upside down in relation to the pic in the link you posted.
Last edited by RPOZ4Z; Aug 2, 2012 at 04:29 PM.
Burning Brakes
Joined: Dec 2010
Posts: 848
Likes: 60
From: CA
Yep, it's an 8.
So, with this we know the housing was cast on September 10th, 1968 (I 10 8) and the axle was assembled on the 265th day of 1968 (Saturday, September 21st, 1968) and installed in an early 1969 350 Corvette (probably an L46 with an M21 Muncie 4 speed).
Ed
So, with this we know the housing was cast on September 10th, 1968 (I 10 8) and the axle was assembled on the 265th day of 1968 (Saturday, September 21st, 1968) and installed in an early 1969 350 Corvette (probably an L46 with an M21 Muncie 4 speed).
Ed
Burning Brakes
Joined: Dec 2010
Posts: 848
Likes: 60
From: CA
You bet. That's a nice ratio for performance, but not too good on gas mileage. If you want something like a 3.36 or even a 3.08, I'm sure there are lots of guys that would be willing to trade!!
Ed
Ed
Last edited by restoman1; Aug 2, 2012 at 05:22 PM.
1st Gear
Joined: Feb 2018
Posts: 1
Likes: 0
I am trying to determine year of this rear end assembly and third member.
Last edited by Mr___Bob; Feb 6, 2018 at 02:47 AM. Reason: Additional info. Only numbers I see are 18214 and 42861. And on torque tube I see 14041 and 925-AR D173.
