Need help with decoding 8 3/4 rear end casting numbers

[68GCHECK]

PLease help with decoding this rear end casting numbers:

 

[khryslerkid]

2070742 =1961-1969 "742"

http://www.mymopar.com/Mopar8_75RearEndGuide.htm

 

[68GCHECK]

OK, thanks.

I'll be more specific:

What is the decodong for these:
1) What is the "2" in the upper left?
2) What is the circled "A"?
3) What is what looks like the "AAPW"?
4) What is the "114"
5) What is the cluster of three or four circles?
6) What is the large "2" on the right hand side?
7) How can I verify that this is a numbers matching rear end besides the casting # "2070742"

I have a 1968 Coronet R/T 440

Thanks
Wally

 

[68GCHECK]

bump

 

[detmatt1]

Almost everything on there will be found on every 742 case. The "114" is a date code which I think just includes the month and day. The best you can do is compare that date code to that of the car. If it's within a couple of months before the spd of the car it's likely correct.

 

[68GCHECK]

bump

 

[68GCHECK]

bump

 

[Mocajava]

The gear ratio may still be on a separate tag that usually is on one of the case mounting bolts.

 

[detmatt1]

Since the 489 cases have big "9"s cast on both sides and all of the 742's have big "2"s cast on both sides it's likely that they were just the last digit of the part # and made big so they were quickly identifiable. That's my guess. All of the 741 cases have a big "X" on both sides, why not a "1"? I don't know...
Again your 114 is the date code.
The other symbols are likely foundry or supplier marks, all relatively inconsequential stuff.

 

[68GCHECK]

Then there isn't a specific way to identify the rear end as numbers matching?

It seems that you can only identify the rear as as being correct for the car by using the rear end part number (742) and of course the date code has to precede the build date.

 

[detmatt1]

That's correct, all of those castings are the same except that date code. The one in my Imperial is identical to yours.

 

[khryslerkid]

If you have the info on what gear ratio and if it was an open or limited slip, that was original to your car, you would have "some" evidence that it is the original rear if it matches . Most cars with the incorrect rear, might be from the owner wanting a different gear ratio or a limited slip.

 

[69L48Z27]

To add on... if it's the 'original' rear you can check the ring gear, that has good dates codes with MMDDYY clearly stamped.

 

[t trucker]

is there amopar rear 348 found tag in car