What rear diff do i have?

Reply Subscribe

Thread Tools

Search this Thread

Mar 21, 2008 | 10:43 PM

383tpimachine

Thread Starter

Drifting

Joined: Feb 2008

Posts: 1,267

Likes: 27

From: Texas

What rear diff do i have?

I looked at the RPO codes under general info and couldnt figure out what rear I had.
its an 85 and by the RPO post It has to have a G44 or G36 right?
maybe im just being a newb since i dont know codes
can anyone help?

Mar 21, 2008 | 10:49 PM

Corvette Chris

Le Mans Master

Joined: Mar 2006

Posts: 5,262

Likes: 0

From: E. Amherst NY

What transmission does your car have?

Mar 22, 2008 | 12:03 AM

combustables

Pro

Joined: Mar 2004

Posts: 553

Likes: 6

From: Northern VA

If your car has an auto trans it has a dana 36. If it has a manual trans it has a dana 44. The search function is your best friend. At your age, I was WALKING.

Mar 22, 2008 | 12:10 AM

wayne lowry

Melting Slicks

Joined: Feb 2006

Posts: 2,240

Likes: 0

From: Cleveland OHIO

By the center bolt in the top of the rear cover. The D36 has one, the D44 doesn't. D36 = 9 cover bolts. D44 = 8 cover bolts. All autos had the D36. 1985 and up manuals had the D44. RPO "G87" Since these cars are old and some have been modded the best way to see what YOU have is to climb under it and check it out. A Dana 44 swap in an automatic car is not uncommon.

Mar 22, 2008 | 12:15 AM

383tpimachine

Thread Starter

Drifting

Joined: Feb 2008

Posts: 1,267

Likes: 27

From: Texas

Its an Automatic
and i looked with the search and everything just didnt understand it
so the Dana 36 was a 2.59 right?

Mar 22, 2008 | 12:23 AM

wayne lowry

Melting Slicks

Joined: Feb 2006

Posts: 2,240

Likes: 0

From: Cleveland OHIO

G44 - 3.07 Rear Axle Ratio
G87 - ring gear 8.50 inch
G92 - Performance Axle Ratio
GHO - 3.54 axle ratio
GM1 - 2.59 Rear Axle Ratio
GM3 - 3.45 Rear Axle Ratio (8.5 in. Ring Gear)
GT7 - 3.33 rear axle ratio
GU2 - 2.73 Rear Axle Ratio

Last edited by wayne lowry; Mar 22, 2008 at 12:26 AM.

Mar 22, 2008 | 10:57 AM

383tpimachine

Thread Starter

Drifting

Joined: Feb 2008

Posts: 1,267

Likes: 27

From: Texas

And now comes my most newb question
The RPO code is the VIN right?
thats what i have been thinking and maybe thats why NONE of those codes appear to me

so is the VIN the RPO?

Mar 22, 2008 | 11:06 AM

toptechx6

Safety Car

Joined: Jun 2006

Posts: 3,629

Likes: 28

From: FL

You can answer a lot of your own questions if you take the time to read the Technical Summary at the top of this forum section and the one on RPO codes at the top of the C4 General forum.

Corvette Stories

The Best of Corvette for Corvette Enthusiasts

10 Ugly Corvettes That We Still Kinda Love

Joe Kucinski

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

Brett Foote

10 Things Every Corvette Owner Needs (2026 Edition)

Michael S. Palmer

8 Most "Only Corvette Owners Understand" Quirks and Problems

Pouria Savadkouei

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Joe Kucinski

How Much Horsepower Every Corvette Engine "LOST" in 1972

Joe Kucinski

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Michael S. Palmer

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Joe Kucinski

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Joe Kucinski

8 Coolest Corvette Pace Cars (and Replicas) of All Time

Verdad Gallardo

Mar 22, 2008 | 11:11 AM

Aurora40

Le Mans Master

Joined: Apr 2005

Posts: 6,413

Likes: 9

From: The Old Dominion

Quote:

Originally Posted by 383tpimachine

And now comes my most newb question
The RPO code is the VIN right?
thats what i have been thinking and maybe thats why NONE of those codes appear to me

so is the VIN the RPO?

Open your center console and look under the lid. There is a a label there with the RPO's listed. The VIN doesn't have any RPO's in it.

Mar 22, 2008 | 11:23 AM

#10

383tpimachine

Thread Starter

Drifting

Joined: Feb 2008

Posts: 1,267

Likes: 27

From: Texas

OK thanks
but there is a really big problem with the center console
NO STICKERS or anything for that matter
so im guessing only way now is to open up the rear?

Mar 22, 2008 | 11:25 AM

#11

Aurora40

Le Mans Master

Joined: Apr 2005

Posts: 6,413

Likes: 9

From: The Old Dominion

Or look at the revs when cruising at a given speed.

Mar 22, 2008 | 11:26 AM

#12

JackDidley

Race Director

Joined: Sep 2003

Posts: 16,838

Likes: 341

From: Database Error Indiana

Click for RPO codes.

http://forums.corvetteforum.com/showthread.php?t=956104

Mar 22, 2008 | 11:30 AM

#13

383tpimachine

Thread Starter

Drifting

Joined: Feb 2008

Posts: 1,267

Likes: 27

From: Texas

Cant check the RPM yet since engine isnt back in it
With the 2.59 at 70 i should be looking at about 1400-1600 right?
Will stroking the 350 to 383 increase rpm? or will it be the same as stock?

Mar 22, 2008 | 12:01 PM

#14

clf93lt1

Pro

Joined: Jan 2005

Posts: 520

Likes: 0

From: Richmond Va

jack up the rear of the car, turn the rear wheel one full turn and count how mant times the drive shalf turns. if it turns 2 1/2 times its a 2.59 if it turns 3 times it a 3.07.

Last edited by clf93lt1; Mar 22, 2008 at 12:09 PM.