Identifying 95 1500 rear end diff?

[95v6fullsize]

Hey guys, I was wondering how (if possible) I could check to see which rear-end differential is on my brothers 95 1500 4.3 automatic. Im pretty sure Its a long geared open diff, just wondering how i can check the gear ratio and open/lsd diff w/o removing or openeing the differential.

 

We are looking to find a slightly shorter lsd to put on his truck...

[HawkScot]

If he is the original owner, decode the RPO codes in the glovebox and see what you have...

[95v6fullsize]

he is not the original owner, how can we check which differntial is on the truck without removing or opening the diff?

[GMstrong]

Look in the glove box like the above post says.You more then likely have 3:42's.

[95v6fullsize]

thank you!

[LeoS41280]

This takes 2 people. Raise one tire and put a chalk mark on it. Put another chalk mark on the driveline. Have one person turn the tire 20 times while the other counts how many times the driveline turns. 34 times and a little means it's a 3.42. 41 turns = 4.11. 32 and 1/4 turns = 3.23. 37 and 1/4 = 3.73. Get the idea?

[95v6fullsize]

Look in the glove box like the above post says.You more then likely have 3:42's.

 

 

Well I finally got around to going to my brothers house, looked in his glovebox and holy cow! How do I decypher these codes to tell which diff is on his truck?

[GMstrong]

Look for one of these codes.

GU4:3:08

GU5:3:23

GU6:3:42

GT4:3:73