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The format is Prefix (application code), month, day and year.
In your case 2 which is not typical, AU(possibly) 7 (July) 26 ( 26th of the month) 4 (possibly 1964 or 74).
This raises several questions with the information as stated.
The July 26 of '64 could be a fit if your car is a very early build '65.
But then AU would not as big blocks were not available until February of '65. I doubt they were building production big block difs that early.
Then there is that first character 2. This is not not typical for a midyear Corvette. In the later years the differential stamp format changed and had more characters. I am not really familiar with them. But I I do know that by 1970 the application code had 3 alpha characters. So this does not fit the 1974 scenario.
What is the VIN of your car?
Can you post a nice clear picture of the stamp?
Last edited by Rumblegutz; 03-19-2017 at 12:43 PM.
The format is Prefix (application code), month, day and year.
In your case 2 which is not typical, AU(possibly) 7 (July) 26 ( 26th of the month) 4 (possibly 1964 or 74).
I agree with some of what you're saying here.
Some rears had a number prefix, to indicate which shift the rear was assembled during. In this case the "2" would be the second shift. Additionally, from my experience, Warner usually stamped the year using two digits not one, making the date July 2nd, not July 26th.
"AV" was the code for a big block 3:08 Posi rear, in 68 and part of 69. Could the date code be 7269, instead of 7264????
This is much more plausible, since AV is a rear end code used in 68-69, and 68-69 rears typically had shift stamped in them, while 63-67 usually didn't.
Some rears had a number prefix, to indicate which shift the rear was assembled during. In this case the "2" would be the second shift. Additionally, from my experience, Warner usually stamped the year using two digits not one, making the date July 2nd, not July 26th.
"AV" was the code for a big block 3:08 Posi rear, in 68 and part of 69. Could the date code be 7269, instead of 7264????
This is much more plausible, since AV is a rear end code used in 68-69, and 68-69 rears typically had shift stamped in them, while 63-67 usually didn't.
Your right. Good catch on the year date format. My bad.
I think your right on the AV code. I had a quick look in source material but missed it. Probably because I was looking at 1970. My bad again.
As I said I knew the format changed in later years. I just couldn't recall how it went. I was thinking I was mistaken about the shift when I saw the 3 character application code in '70 and later. Seemed like a lot of stuff in one stamp. Again, my bad.
I know a little about '67 and earlier. But that little bit drops way off for '68 and later.
The format is Prefix (application code), month, day and year.
In your case 2 which is not typical, AU(possibly) 7 (July) 26 ( 26th of the month) 4 (possibly 1964 or 74).
This raises several questions with the information as stated.
The July 26 of '64 could be a fit if your car is a very early build '65.
But then AU would not as big blocks were not available until February of '65. I doubt they were building production big block difs that early.
Then there is that first character 2. This is not not typical for a midyear Corvette. In the later years the differential stamp format changed and had more characters. I am not really familiar with them. But I I do know that by 1970 the application code had 3 alpha characters. So this does not fit the 1974 scenario.
What is the VIN of your car?
Can you post a nice clear picture of the stamp?
VIN 194675S109112 I do not know how to post a photo but the stamp is very clear 2AV7264
The format is Prefix (application code), month, day and year.
In your case 2 which is not typical, AU(possibly) 7 (July) 26 ( 26th of the month) 4 (possibly 1964 or 74).
This raises several questions with the information as stated.
The July 26 of '64 could be a fit if your car is a very early build '65.
But then AU would not as big blocks were not available until February of '65. I doubt they were building production big block difs that early.
Then there is that first character 2. This is not not typical for a midyear Corvette. In the later years the differential stamp format changed and had more characters. I am not really familiar with them. But I I do know that by 1970 the application code had 3 alpha characters. So this does not fit the 1974 scenario.
What is the VIN of your car?
Can you post a nice clear picture of the stamp?
VIN 194675S109112 I do not know how to post a photo but the stamp is very clear 2AV7 2 64 spacing like I have printed. The case has 8 bolts and it counts out just a tick over 3:1 ??????? I'm confused but it is a posi.
VIN 194675S109112 I do not know how to post a photo but the stamp is very clear 2AV7 2 64 spacing like I have printed. The case has 8 bolts and it counts out just a tick over 3:1 ??????? I'm confused but it is a posi.
I just looked at a wilcox list of rear axles and they do show a 3.08:1 for a 4 speed 327 posi for 1965 but the code is AL. My guess is that is what is in this car.
Some rears had a number prefix, to indicate which shift the rear was assembled during. In this case the "2" would be the second shift. Additionally, from my experience, Warner usually stamped the year using two digits not one, making the date July 2nd, not July 26th.
"AV" was the code for a big block 3:08 Posi rear, in 68 and part of 69. Could the date code be 7269, instead of 7264????
This is much more plausible, since AV is a rear end code used in 68-69, and 68-69 rears typically had shift stamped in them, while 63-67 usually didn't.
The axle stamping reads 2AV7 2 64 with spaces as I have typed it. If I follow the coding correctly it is a July 2nd 1964 build date on the axle. The V has to be a mis-stamp I think an L would have been a 3.08:1 ratio which is what it counts out to be. It is a posi for sure. I think the car was built in Feb 1965. Who knows what the car was born with? I was hoping it was a 3.70:1 because that is what I was led to believe when I purchased the car.
The trans and engine are numbers matching just not sure about that rear diff. Any comments are appreciated.
Now I hope someone can help make some sense out of the stamping. As I previously said it counts out to be a 3.08:1 posi and the car was born on feb 8th 1965 according to the reseach that I have done.
Any chance you can see the raised date casting on the housing, drivers side, just above the strut rod bracket? Very difficult to see with everything in place.
Here's a pic taken from a CL ad showing the raised casting date.
Mike T - Prescott AZ
Any chance you can see the raised date casting on the housing, drivers side, just above the strut rod bracket? Very difficult to see with everything in place.
Here's a pic taken from a CL ad showing the raised casting date.
Mike T - Prescott AZ
Yes very hard to see but it looks like CONI the last digit might be a 1 or large case i They are all raised letters or numbers and there are to little raised casting marks before and after like *CONI*
Yes very hard to see but it looks like CONI the last digit might be a 1 or large case i They are all raised letters or numbers and there are to little raised casting marks before and after like *CONI*
Where your picture has a number that looks like E185 mine has no numbers at all in that location
Your right. Good catch on the year date format. My bad.
I think your right on the AV code. I had a quick look in source material but missed it. Probably because I was looking at 1970. My bad again.
As I said I knew the format changed in later years. I just couldn't recall how it went. I was thinking I was mistaken about the shift when I saw the 3 character application code in '70 and later. Seemed like a lot of stuff in one stamp. Again, my bad.
I know a little about '67 and earlier. But that little bit drops way off for '68 and later.
I believe you've nailed it. Good one
Now that I know the axle ratio does count out to be a 3.08:1 which matches the AV code doe the other numbers make sense?
2AV7 2 64 spaced like I typed it.
Now that I know the axle ratio does count out to be a 3.08:1 which matches the AV code doe the other numbers make sense?
2AV7 2 64 spaced like I typed it.
I'm sorry, but I don't think any of the codes or dates line up.
"AV" does not match a 3:08 rear for your car, because AV was not used in 1965. It was only used as a 3:08 Posi with 68 and 69 427's. In 65 the codes for a 3:08 rear were; "AR" for the open 3:08, "AL" for 3:08 Posi with a 327, and "AT" for the 3:08 Posi with a 396.
Additionally, your VIN indicates that your car was built in Feb. 65, and that rear is dated July, 64. This is almost 7 months before the car was built, and outside of what's considered a normal time line for parts used in production. Even if the "V" is a miss stamp, the assembly date is abnormal too.
It would be helpful if you could find the casting date for the rear, and maybe the one on the rear end cover too.
I'm sorry, but I don't think any of the codes or dates line up.
"AV" does not match a 3:08 rear for your car, because AV was not used in 1965. It was only used as a 3:08 Posi with 68 and 69 427's. In 65 the codes for a 3:08 rear were; "AR" for the open 3:08, "AL" for 3:08 Posi with a 327, and "AT" for the 3:08 Posi with a 396.
Additionally, your VIN indicates that your car was built in Feb. 65, and that rear is dated July, 64. This is almost 7 months before the car was built, and outside of what's considered a normal time line for parts used in production. Even if the "V" is a miss stamp, the assembly date is abnormal too.
It would be helpful if you could find the casting date for the rear, and maybe the one on the rear end cover too.
The number on the rear cover would only be visible to me if I drop the top of the spare tire compartment down from the car. That is the only other number that I have been able to find on either housing. Could it be that it is an axle from a 396 posi despite the July 64 date? What makes the 396 axle different from a 327?
BB rear ends have heavy duty side yolks or ones that get a cap that's bolted to the yolks rather then the strap like on SB rears. If the rears been apart it can be changed. But the bolted side yolks are sought after becouse are stronger. So not sure why one would change that
I know this is an old post, but if anyone is using it for research:
I think it is a 1969 production year AV coded rearend, originally lightly stamped “68”. The someone has lightly ball peen hammered over top of the 8 and stamped a 4 over it to make it work better in a ‘65 car. They may have tried to restamp the 6 deeper as well as I don’t think the ghosted 6 in the background is the same font, and you don’t see ghost stamps or bounces on rearends very often.
03-18-2017, 06:19 PM
1965 rear axle codes
