Rear end gear ratio

Look for an aluminum tag on a rear diff cover bolt, it will have the info if its still there

Check your glove box it should be a whole bunch of three- lettered codes in there the first call him to the very left about 4 down should start with a G probably says GT4 which is 373 otherwise take the cold call your dealer and they will know

They only used to gear ratio is in the 2001 1 is a 373 the code is GT4 and the other is a 410 and I'm not sure what the code is

RPO Code Description Ratio G11 Transaxle Final Drive 2.56 G44 Axle Rear 3.07 G72 Axle Rear 2.14 G75 Axle Rear 3.62 G76 Positraction Rear G80 Axle Positraction, Limited Slip G81 Positraction Rear Axle G82 Axle Rear 4.56 G84 Axle Rear 4.10 G86 Axle Rear, Limited Slip G87 Ring Gear, 8.5″ G89 Ring Gear, 7.5″ G90 Rear 3.15 G91 Special Highway Rear Axle 3.08 G94 Axle Rear 3.31 G96 Axle Rear 3.55 G97 Axle Rear 2.73 GH0 Axle Rear 3.54 GH2 Axle Rear 2.29 GH3 Axle Rear 2.77 GH4 Axle Rear 2.92 GH7 Axle Rear 2.73 GJ1 Axle Rear 5.38 GJ2 Axle Rear 5.13 GK7 Axle Rear 4.78 GK8 Axle Rear 4.33 GK9 Axle Rear 4.63 GL0 Axle Rear 5.13 GL3 Axle Rear 6.17 GM1 Axle Rear 2.59 GM2 Axle Rear 3.44 GM3 Axle Rear 3.45 GM4 Axle Rear 3.67 GM5 Axle Rear 3.89 GM6 Axle Rear 4.22 GM7 Axle Rear 3.68 GM8 Axle Rear 2.56 GN9 Axle Rear 4.11 GS1 Axle Rear 2.73 GS3 Axle Rear 3.73 GS4 Axle Rear 3.70 GS5 Axle Rear 4.11 GS6 Axle Rear 4.56 GS8 Axle Rear 3.94 GT1 Axle Rear 2.56 GT2 Axle Rear 2.29 GT4 Axle Rear (Dup of 5X1) 3.73 GT5 Axle Rear (Dup of GT8) 4.10 GT7 Axle Rear 3.33 GT8 Axle Rear (Dup of GT5) 4.10 GU1 Axle Rear 2.41 GU2 Axle Rear 2.73 GU3 Axle Rear 2.93 GU4 Axle Rear 3.08 GU5 Axle Rear 3.23 GU6 Axle Rear 3.42 GU7 Axle Rear 2.77 GU8 Axle Rear 3.90 GU9 Axle Rear 3.91 GV0 Axle Rear 3.55 GV1 Axle Rear 2.73 GV2 Axle Rear 5.83 GV3 Axle Rear 3.08 GV4 Axle Rear 3.36 GV5 Axle Rear 3.55 GV7 Axle Rear 4.11 GV8 Axle Rear 2.72 GV9 Axle Rear 4.25 GW2 Axle Rear 2.56 GW3 Axle Rear 2.56 GW4 Axle Rear 3.31 GW5 Axle Rear 2.73 GW6 Axle Rear 3.27 GW8 Axle Rear 4.10 GW9 Axle Rear (Dup of GU3) 2.93 GX1 Axle Rear 3.70 GX2 Axle Rear 3.07 GX3 Transaxle Final Drive 3.33 GX4 Axle Rear 3.75 GX5 Axle Rear 4.09 GX6 Axle Rear 3.53 GX8 Transaxle Final Drive 3.74 GY2 Axle Rear 3.31 GY3 Transaxle Final Drive 4.29 GY4 Axle Rear 4.53 GY5 Axle Front 3.65 GY7 Transaxle Final Drive 4.18 GY9 Axle Rear 4.31 GYS Transaxle Final Drive 3.65 H01 Axle Rear 3.07 H04 Axle Rear, Single Speed 4.11 H05 Axle Rear 3.73 H12 Axle Rear, 21000 Lbs, Eaton 21065S, Single Speed H42 Axle Rear 6.17 H43 Axle Rear 5.43 HA3 Axle Rear, Single Speed 5.29 HC4 Axle Rear 4.56 HC7 Axle Rear, 7500 Lbs, Single Speed 2.38 HC8 Axle Rear, Single Speed, Truck 3.21 HC9 Axle Rear 5.13 HE3 Axle Rear, 3500 Lbs, Single Speed 3.07 HE4 Axle Rear 3.40 HF7 Axle Rear, 10000 Lbs, Dana 70, Single 4.56 HF8 Axle Rear 4.88 HJ1 Axle Rear 4.55 HJ2 Axle Rear 5.86 HJ3 Axle Rear 4.75 HJ4 Axle Rear 6.50 HJ5 Axle. 5.57 HJ6 Axle Rear 4.78 HJ7 Axle Rear 4.88 HK1 Axle Rear 2.87 HK3 Axle Rear 6.14 HK9 Axle Rear 10000 Lbs, Single Spd 5.86 HO4 Axle Rear 4.11 HO6 Axle Rear 4.63

I have a 2001 gmcsierra 1500 extended cab 4x4

Shawnwlathem did you ever figure out which rear end you had?