# 1964 GTO Rear axle casting number ID



## mike64gto (Jun 12, 2009)

I have searched all over the place and cant find the asnwer.
Can someone tell me that year this casting number is for?
9779822, its a narrow (64-65) 10 bolt.
Thanks,Mike


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## 68greengoat (Sep 15, 2005)

I've attached a link for GTO axle codes. Even tho it doesn't list the casting numbers, you may be able to take the information and figure out what you have. They list the locations for each of the various codes.... May or may not help....

GTOAxleCodes


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## PontiacDave (Jun 9, 2009)

I have a '65 GTO with the original rear diff and so does another buddy of mine and both of the casting #'s on our diffs are the same as yours. Most likely the center section casting #'s was the same for most '64-66 as these were all essentially the same. The difference came in 1967.....it got a little wider among other minor upgrades. You need to find the cast date code that should be near the casting #'s and see what year the diff is.


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## mike64gto (Jun 12, 2009)

*Pic of Casting*

August 1964?


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## monzaz (Dec 23, 2008)

*gto pontiac rear end housing*

I know this is a OLD thread - but the early 1964- 65 Housings were really Olds mobile housings. They had 2 lower castring webbing with a vertical webbing from the pinion yoke back to the passenger upper control arm mount melting into the casting... ONLY on the passenger side. Casting numbers were on the BOTTOM of the center section facing the ground. 64 was 9773722 X they there was your number also. 

The seal used on the rear was 8620 seal different than the later 1966 -1972 which was 2043 seal - SO yokes were obviously different too. THEY were all 27 spline yokes just a different seal diameter. In 1967 all Pontiac rears were 1" wider than all 1966 and older rears.


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