12 bolt decode help [Archive] - Team Camaro Tech

: 12 bolt decode help


purecam
May 16th, 12, 06:11 PM
Just found a 12 bolt with a casting number of 3894939. I also found Cf 0901. Not sure what it's from but it looks like chevelle by the spring mounts.. Anybody have any ideas?

bcm66
May 16th, 12, 06:24 PM
That is for a 67 Chevelle, one year only casting number. Should have to "ears" on upper part of center section for control arms. CF is 3.31 posi.

3.31 was the standard ratio for the 1967 Chevelle with 396/325hp engine and manual transmission without AC.

Mickeystoys69RSSS
May 16th, 12, 06:24 PM
Rear axle code CF was used in 1965-1969 Chevelles and is a 3.73 posi traction.

bcm66
May 16th, 12, 06:31 PM
Nope. CF is 3.31 posi in all of those years. Trust me. I have one in my Chevelle.

purecam
May 16th, 12, 06:32 PM
Ok, I may try to sell it over on the chevelle site... Thanks!

purecam
May 16th, 12, 06:35 PM
Do you mean 3994938? If so that is for a 67 Chevelle, one year only casting number. Should have to "ears" on upper part of center section for control arms. CF is 3.31 posi.

3.31 was the standard ratio for the 1967 Chevelle with 396/325hp engine and manual transmission without AC.

Double checked casting no... It is 3894939 with an n above it..

bcm66
May 16th, 12, 06:40 PM
Double checked casting no... It is 3894939 with an n above it..

You are right. I had a typo.

3894938 is the 10 bolt center section casting number.

3894939 is the 12 bolt center section casting number used for most of the 1967 model year.

purecam
May 16th, 12, 06:42 PM
Any idea of an asking price? Looks like it has strange brand axles.

Mickeystoys69RSSS
May 16th, 12, 06:47 PM
That depends on the condition. Does it need to be rebuilt, or is restored?

purecam
May 16th, 12, 07:02 PM
Looks good.. Definitely needs a cleaning... I pulled the cover and everything looks great inside...

Mickeystoys69RSSS
May 16th, 12, 07:18 PM
I would guess $800-$1000 once it is cleaned up and painted.

bcm66
May 17th, 12, 07:08 AM
Looks good.. Definitely needs a cleaning... I pulled the cover and everything looks great inside...

Original GM gears inside? If so, check the numbers on the ring gear.