id rear end

i'm new to this site and i'm wondering how to id a 2001 gmc jimmy rear end. i know it's a 3.42 but not sure if it's a 8.?? or 7.?? is there a tag somewhere that will tell me. it has 10 bolts holding the cover on both may have the same amounts i'm not sure .any thing would be helpfull. thank you s/t :feedback:

Check the RPO codes on a black and white sticker in the glove box. RPO codes are 3 character codes that tell every component that is installed on the vehicle. Post any that start with "G" and we can tell you what axle you have.