Does anyone know what rear end came in the 89GTAs with the 5.7L tpi? I thought all this time I had a 3.73 and now I just don't know. I looked on the axel to the left of diff (pass) side and it's cleaned to the metal and there is no stamped marking as Haynes says there should be. I did find a stamp on the bottom of diff that is G16e8 whatever that means. It is a posi, that much I do know!

 

The 89 GTA with a 5.7L TPI will have a Borg Warner 9 bolt diff. It will have 3.27 gears and a posi.

For more info on the 9 bolt, www.diffsolutions.com

 

Standard rear for 350 TPI was a BW 9-bolt with 2:77 ratio the 3:27 was a extra cost option. Most dealer ordered cars had the 2:77.

 

I forgot to say it was a 10 bolt so what does that tell me?
thanks for the reply.

 

Unless it was changed, you bought a 305 TPI car with a 2:73 10-bolt rear. Check your Vin for the original engine, reason no 88 350 TPI came stock with a 10-bolt.

 

I let my sons count it and well some of you know what I mean, 15 yrs old. So I went out and counted nine bolts so what do I have 2:77 or the 3:27? Is there a way to check for sure by using Vin code? your right it s a BW

 

I let my sons count it and well some of you know what I mean, 15 yrs old. So I went out and counted nine bolts so what do I have 2:77 or the 3:27? Is there a way to check for sure by using Vin code?

 

Check the RPO list located under the console lid for these Codes:
GH3 = 2:77 BW rear axle ratio
GW6= 3:27 BW rear axle ratio
G80= Limited slip rear

Note: The Vin will only indicate the original engine installed at the factory.

 

thanks DJP I checked the RPO And I have the GW6 3.27 gear and the G-80 posi. Once you told me where to look it was pretty simple but I won't be arrested for removing the do not remove tag I hope.