2:73 gears under 2500truck???

[Karen512]

I was wondering what the Chevrolet/GMC 2500 trucks in 1998 have under them. I have been told they have 2:73 gears, is that true? I am considering replacing my differential and "upgrading" to 3:73 gears. Any thoughts or comments, pros/cons to the switch??

[Jeremy-WI]

Check your RPO codes in your glove box. The ones starting with GU or GT are usually gear ratio codes, just post them here

[shep1111]

Look at your RPO codes in your glove box, GT4, 3.73 ratio, and GT5, is a 4.10 ratio, should be the only two available on your truck.

[Karen512]

I looked in the glove box. There were only a bunch of letters, no numbers or codes. Guess I 'll have to look up the specs on the internet. Will post them if I can find them.

[Karen512]

Still no luck looking on the internet. Anybody know of a site that would list differential specs?????????????

[shep1111]

open your glove box, and on the inside there should be a sticker saying "service parts identification", it will have your VIN number and a lot of three digit number, or number letter, or letter combinations. See if one of them is one of the above in my former reply. If you have a limited slip rear axle, you will find a G80, the axle ratio will be right before this one.