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Discussion Starter #1
I was told when I bought my "65" with a 4 speed transmission that it has 3.55 gears on a Posi. After wire wheeling the right axle tube I cannot find any code, I've gone from the differential to the shock mount and have not been able to find any factory stamps. Ideas?

Also, on the differential itself there are the these numbers cast into the differential itself:

Left Side
CFD
2
Right Side
336 (or 8)
9788202


Thoughts?

Steve
 

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Believe you have misread the casting number. it's fairly easy to do, 8's, 9's, 3's all look fairly close when degraded from rust, poor casting transfer, or globs of paint, the worst is powdercoat.

9799202 is a later Pontiac 8.2 10 bolt out of a '70-72 Pontiac Abody. As a mid '66 and later Pontiac 8.2 10 bolt, it is 1/2" wider on each side than the original '65 Pontiac 8.2 10 bolt which would have casting number 9779822. The "202" is a better rear, nodular casting, and will have tapered bearing axles.
 

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Discussion Starter #3
You are correct, I did misread the casting number. I re-checked this AM and the number is 9799202.

As this is a later Pontiac 8.2 10 bolt out of a '70-72 Pontiac A-body, any idea where I can look for the axle code?
 

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On the code location, believe front of pass side axle tube. Will go out and double ck on some '71 & 72 partscar roller rearends, I haven't cleaned or gone through a '70-72 Pontiac 8.2 rear in quite a while, instead build the 8.5's.
 
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