All GMs have a parts ID sticker. Some are in the glovebox like on your truck. Little white sticker with a bunch of funny numbers lol Other are on the spare tire cover. I forget which codes you are looking for but they are all there in 3 digit code I think it's JB7 or JB8 but the dealer or Google can help you decipher it to get the answer without opening the diff
Do you know the gear ratio? You also should tell us the engine size, auto or manual transmission, and which transmission. You can also take the VIN to a GMC dealer. They may beable to pull the build sheet and tell you what you need to know.
Answers & Comments
All GMs have a parts ID sticker. Some are in the glovebox like on your truck. Little white sticker with a bunch of funny numbers lol Other are on the spare tire cover. I forget which codes you are looking for but they are all there in 3 digit code I think it's JB7 or JB8 but the dealer or Google can help you decipher it to get the answer without opening the diff
Do you know the gear ratio? You also should tell us the engine size, auto or manual transmission, and which transmission.
You can also take the VIN to a GMC dealer. They may beable to pull the build sheet and tell you what you need to know.