79 Diff Gears
Thread Starter
5th Gear
Joined: Aug 2002
Posts: 5
Likes: 0
From: Evansville IN
79 Diff Gears
How do I identify which carrier is in the Diff on the '79 Vette? I'm looking to go to about a 4.10:1 or 4.56:1 ratio in the rear. I've looked at vendor's sites and they specify a series 3 or series 4 carrier. How do I know which I have? Is there a place where I can enter the VIN and get this info?
The VIN is 1Z3789S421598.
Thanks.
The VIN is 1Z3789S421598.
Thanks.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Re: 79 Diff Gears (andyglines)
The vin no has nothing to do with it. What is the gear ratio that is in the carrier. If it is a 3.08 3.36 3.55 or 3.70 ratio you have a 3 series carrier. A 4.10 or 4.56 would be a 4 series carrier. I posted 2 pictures a long time ago showing the 2 carriers side by side. It might still be in the archives. I'm on my laptop so I can't resend them. If you need a 4 series I still have one
Safety Car
Joined: Apr 2001
Posts: 4,795
Likes: 1
From: Regina Saskatchewan, Canada.
Re: 79 Diff Gears (andyglines)
As far as I know they stopped using the 4 series carrier in 1974 because this was the last year that 4.11's were available. My bet is that your 79 still has it's original 3 series carrier meaning you can have you pick of ratio's up to 3.90, anything after that will require a 4 series. On the other hand there is now companies selling what they call thick gears in ratio's like 4.11 and such which fit the 3 series carrier. Using a ring gear spacer in a no no.
Thread Starter
5th Gear
Joined: Aug 2002
Posts: 5
Likes: 0
From: Evansville IN
Re: 79 Diff Gears (Stingy74)
thanks for your posts. The car almost definetly has a series 3 (I would appreciate seeing the pics though). I saw one of the vendors had the thick gears available. Turning the wheel and counting the driveshaft produced 3.4??:1 = not quite 3.5 turns on the drive shaft.
Thanks again for your help.
Thanks again for your help.
