Question - 67 Differential code
Thread Starter
Instructor
Joined: May 2001
Posts: 143
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From: Church Hill Tennessee
Cruise-In III Veteran
Question - 67 Differential code
My 67's differential carrier is stamped with the code AU. My 67 Corvette Specification book doesn't show a code AU. It shows an AO which is a 3.70:1 ratio. The production date of the diff. is stamped as 5 31 67 and the car's build date was 6-9-67. The engine and trans are original and I don't have any reason to believe the differential has been changed. I was just wondering if anyone had any info showing a differential code AU. BTW, I am recovering from gall bladder surgery :( and I'm not physically capable (yet) of breaking into the diff. or pulling the speedo gear out of the trans to determine the ratio of the rear end. The diff. just happed to be sitting in the right position on my garage floor to allow me to see the code and start wondering.
Burning Brakes
Joined: Dec 2002
Posts: 912
Likes: 1
From: San Antonio TX
St. Jude Contributor '03 & '04
Re: Question - 67 Differential code (GRTaylor)
AU: 3.36 posi with 427.
Gary, I don't know if you saw my post where I thanked you for the frame measurements. Very helpful.
Hope you recover quickly.
Gary, I don't know if you saw my post where I thanked you for the frame measurements. Very helpful.
Hope you recover quickly.
Thread Starter
Instructor
Joined: May 2001
Posts: 143
Likes: 0
From: Church Hill Tennessee
Cruise-In III Veteran
Re: Question - 67 Differential code (gary6696)
Gary, I don't know if you saw my post where I thanked you for the frame measurements. Very helpful.
Hope you recover quickly.
Hope you recover quickly.
Burning Brakes
Joined: Dec 2002
Posts: 912
Likes: 1
From: San Antonio TX
St. Jude Contributor '03 & '04
Re: Question - 67 Differential code (GRTaylor)
"Unfortunately, my car had been sitting outside on cinder blocks since 1978"
That's not unfortunate, that's great, cause it means Bubba hasn't worked on it for 25 years.
That's not unfortunate, that's great, cause it means Bubba hasn't worked on it for 25 years.
Thread Starter
Instructor
Joined: May 2001
Posts: 143
Likes: 0
From: Church Hill Tennessee
Cruise-In III Veteran
Re: Question - 67 Differential code (gary6696)
That's true Gary. Bubba had already butchered up the wiring, replaced the starter, alternator, carburetor and fuel pump. He had also broken the alternator bracket and welded it back together. When I tore down the engine, I was disappointed to find it had been apart before. I found a solid lift cam & lifters & dual roller timing chain (The engine is a 427/390), and the rotating assembly had been balanced. Cylinders and rod and main journals on crank are still standard and there is no wear on the cylinder walls, however I'm afraid the surface rust in a couple of the cylinders will require the block to be bored. Looks like Bubba let a professional machine shop do the balance job.
