What Title says.

 

Most likely round ones. Seriously, it depends on the option. Check label in glove box.
RPO CODEDESCRIPTIONF16TransAxle Final Drive F17TransAxle Final Drive F18TransAxle Final Drive F25TransAxle Final Drive F29TransAxle Final Drive F36Axle FrontF45Axle FrontF47Axle FrontF57Axle FrontF62TransAxle Final Drive F67TransAxle Final Drive F68TransAxle Final Drive F75TransAxle Final Drive F77TransAxle Final Drive F79 TransAxle Final Drive F82TransAxle Final Drive F83TransAxle Final Drive F90Axle FrontFA0RearFA1Rear 2 SPEEDFA2Rear 2 SPEEDFH5TransAxle Final DriveFH6Axle FrontFH7TransAxle Final DriveFH8Axle FrontFH9TransAxle Final Drive FJ1Axle FrontFJ2Axle FrontFJ3TransAxle Final DriveFJ4Axle FrontFJ5Axle FrontFJ7Axle FrontFP0TransAxle Final Drive FP1TransAxle Final Drive FP2TransAxle Final Drive FP3TransAxle Final Drive FP4TransAxle Final Drive FP5TransAxle Final Drive FP6TransAxle Final Drive FP7 TransAxle Final Drive FP8TransAxle Final Drive FP9TransAxle Final Drive FQ2TransAxle Final Drive FQ3TransAxle Final DriveFQ4TransAxle Final DriveFQ6 TransAxle Final Drive FQ8TransAxle Final Drive FQ9TransAxle Final Drive FR2TransAxle Final Drive FR3TransAxle Final Drive FR6TransAxle Final Drive FR7TransAxle Final Drive FR8Axle FrontFR9TransAxle Final Drive FV0TransAxle Final Drive FV1 TransAxle Final Drive FV2TransAxle Final Drive FV3TransAxle Final Drive FV4TransAxle Final Drive FV5TransAxle Final DriveFV6TransAxle Final DriveFV7TransAxle Final DriveFV8TransAxle Final DriveFV9TransAxle Final DriveFVOTransAxle Final Drive FW2TransAxle Final Drive FW3TransAxle Final Drive FW4 TransAxle Final Drive FW5 TransAxle Final Drive FW6 TransAxle Final Drive FW7TransAxle Final Drive FW8TransAxle Final Drive FW9TransAxle Final Drive FWSTransAxle Final Drive FX1TransAxle Final Drive FX2TransAxle Final Drive FX4TransAxle Final Drive FX8TransAxle Final Drive FY1TransAxle Final Drive FY3TransAxle Final Drive FY5TransAxle Final Drive G11TransAxle Final Drive G44 Axle Rear G72Axle RearG75Axle RearG76Positraction Rear
G80Axle Positraction, Limited Slip
G81Positraction Rear Axle
G82Axle RearG84Axle RearG86Axle , Rear, Limited Slip
G87Ring Gear, 8.50 Inch
G89Ring Gear, 7.50 Inch
G90RearG91Special Highway Rear Axle G94Axle RearG96Axle RearG97Axle RearGH0Axle RearGH2Axle RearGH3Axle RearGH4Axle RearGH7Axle RearGJ1Axle RearGJ2Axle RearGK7Axle RearGK8Axle RearGK9Axle RearGL0Axle RearGL3Axle RearGM1Axle RearGM2Axle RearGM3Axle RearGM4Axle RearGM5Axle RearGM6Axle RearGM7Axle RearGM8Axle RearGN9Axle RearGS1Axle RearGS3Axle RearGS4Axle RearGS5Axle RearGS6Axle RearGS8Axle RearGT1Axle RearGT2Axle RearGT4Axle Rear (DUP WITH 5 X 1)GT5Axle Rear (DUP WITH GT8)GT7Axle RearGT8Axle Rear (DUP WITH GT5)GU1Axle RearGU2Axle RearGU3Axle Rear2.93GU4Axle RearGU5Axle RearGU6Axle RearGU7Axle RearGU8Axle RearGU9Axle RearGV0Axle RearGV1Axle RearGV2Axle RearGV3Axle RearGV4Axle RearGV5Axle RearGV7Axle RearGV8Axle RearGV9Axle RearGW2Axle RearGW3Axle RearGW4Axle RearGW5Axle RearGW6Axle RearGW8Axle RearGW9Axle Rear (DUP WITH GU3)GX1Axle RearGX2Axle RearGX3TransAxle Final Drive GX4Axle RearGX5Axle RearGX6Axle RearGX8TransAxle Final Drive GY2Axle RearGY3TransAxle Final DriveGY4Axle RearGY5Axle FrontGY7TransAxle Final DriveGY9Axle RearGYSTransAxle Final Drive H01Axle RearH04Axle Rear, SINGLE SPEEDH05Axle RearH12Axle Rear, 21000 LBS, EATON 21065S, SINGLE SPEED
H42Axle RearH43Axle RearHA3Axle Rear, SINGLE SPEEDHC4Axle RearHC7Axle Rear, 7500 LBS, SINGLE SPEEDHC8Axle Rear, SINGLE SPEED, TRUCKHC9Axle RearHE3Axle Rear, 3500 LBS, SINGLE SPEED,HE4Axle RearHF7Axle Rear, 10000 LBS, DANA 70, SINGLEHF8Axle RearHJ1Axle RearHJ2Axle RearHJ3Axle RearHJ4Axle RearHJ5Axle RearHJ6Axle RearHJ7Axle RearHK1Axle RearHK3Axle RearHK9Axle Rear 10000 LBS, SINGLE SPEEDHO4Axle RearHO6Axle Rear

 

All that is assuming no previous owner ever changed your gears from what was factory installed. And considering all the members just here who want to or do change their gears, the RPO code is useless information in those instances. The RPO code will tell you "what could be" or "might still be" in the rearend.

 

Very true, may just have to get down and dirty, take off the differential cover, count the number of teeth on the ring and the pinion gears, and do the unthinkable, like long division. lol

 

Well, the guy I bought it from drive it off the lot in dec of 95. He said he did nothing to it but changed the oil every 2k miles. He had to put a new compressor and window motor, but that's it.

 

In that case check the chart and the sticker in the glove box and look for the GU- code.

 

Did the previous owner ever change the oil in the rearend? If not, you'll want to pop the cover off anyway, and change the oil. And don't forget the limited slip additive.

 

or you can tell me your tire size and engine rpm's at 60mph in the top gear and i can figure it out. is it a manual or automatic?