C2 differential ID

[Michael G.]

AD10B5E0-BEDD-4A7F-9CA7-8F39C4407D5C.jpg

[Mike T.]

Re: C2 differential ID

IMG_4504.jpgIMG_4505.jpgMike - I believe that casting was used for a number of years going up to at least 1969. Can you post up a pic of the date code, found on the drivers side/bottom that should look like a letter followed by numbers. Also a pic of the stamped code on the bottom rear of the housing. It faces the ground and should start with a couple letters followed by numbers. That should tell us the date the housing was cast and the gear ratio. I've just taken a couple pics of the diff in my 65 Roadster as 'an example' to help the OP.

[Jimmy G.]

Re: C2 differential ID

April 26 1965 Cant access what FA code is at the present time

Casting was Jan 29 1965

[Jim D.]

Re: C2 differential ID

Joe Lucia posted in a prior thread - "The GM #3899143 carrier case was used for ALL 1967-79 Corvettes."
Look for a casting date on the drivers side as Mike posted above.

[Michael G.]

Re: C2 differential ID

Here are some more pics:

8C12E3EE-0A8C-44A5-95CA-F9C6D8AAB207.jpg

E35C7144-9AD2-4487-9D30-CEDA13A21540.jpg

[Michael J.]

Re: C2 differential ID

IIRC, FA is a 3.70 to 1 ratio.

[Michael J.]

Re: C2 differential ID

IIRC, AM is a 3.36 to 1 ratio.

[Michael G.]

Re: C2 differential ID

Looks like it was assembled in '67, "AM" is 3.36:1 Posi. That agrees with my measurement of the ratio. Mystified as to why the casting date seems to in be 68...though that '8' is kinda messed up...

[Joe R.]

Re: C2 differential ID

According to the 1953-1972 Specifications Guide Special Membership Edition written by John Amgwert which was Volume 16 NUMBER 1 SUMMER 1989 lists 1965 Corvette FA as 3.70:1 Positraction 4 speed 396.

JR

[Mike T.]

Re: C2 differential ID

Sorry for the confusion guys, the pics I posted of the 65 3:70 diff in my 65 NOM 396 Roadster were only meant to help the original poster see where the raised casting and stamped numbers would be located to help us identify his diff. I think some have thought they were posted by the other 'Mike'.

[Michael G.]

Re: C2 differential ID

We only have three Mikes on this thread, why would anyone be confused

[Mike M.]

Re: C2 differential ID

four mikes on this site mike Garver. u forgot saint Michael.

[Michael G.]

Re: C2 differential ID

Well heck, I had four Mikes at the dinner table last week....

[Tom D.]

Re: C2 differential ID

Mikes: Had a casting like that with a late 1962 casting date. Not sure if I still have it.

Seems many of the early C2s ended up with later differentials. Starting in '65, they lasted longer.

TD "va"

[Mike E.]