1995 GMC Sierra Rear End for 5.7L V8

[LittlSuzi]

I need help! My transmission went out and took my rear diff with it (or maybe it was the other way around?) It happened 4 years ago and due to budget issues we didn't fix her right away. We got a rear diff at our local PickNPull and had the transmission rebuilt but the diff we got at PNP has a different ratio and I'm not sure how to figure out the correct rear diff number. She's a long bed extra cab with the special tow package and a 5.7L V8. I'm the second owner. Is there a number hidden in the VIN?

Edited October 28, 2021 by LittlSuzi
Adding photos of original info

[CamGTP]

The information is right there in the RPO code list in the glove box.

You have a GT4 and G80. That means the factory diff had a 3.73 rear end with a Factory G80 positraction diff.

 

To figure out the gear ratio of the used diff you can remove the cover and count the teeth of the gears. Or put a piece of tape on the tire, rotate the driveshaft by hand with the rear end on jack stands and count how many turns it takes to do a full 360. I believe I am explaining that right, you can youtube a video on it as well.

[LittlSuzi]

44 minutes ago, CamGTP said:

The information is right there in the RPO code list in the glove box.

You have a GT4 and G80. That means the factory diff had a 3.73 rear end with a Factory G80 positraction diff.

 

To figure out the gear ratio of the used diff you can remove the cover and count the teeth of the gears. Or put a piece of tape on the tire, rotate the driveshaft by hand with the rear end on jack stands and count how many turns it takes to do a full 360. I believe I am explaining that right, you can youtube a video on it as well.

Thanks! To be honest I should have read other posts and done more googling first I think I did find everything we need but thanks for the info anyway. I appreciate it!

[Brian Lindsey]

3 years ago i had same problem , my rear diff was soo worn out the teeth on both gears were sharp , my rear diff bound up and took out my transfer case , driveline , and trans adapter, i was in alabama at the time , cost almost 3000 to get it back on road to get it home and finish repairs