Where do you find the axle ratio for a 1999 GMC sierra extended cab?
The axle ratio for a 1999 GMC Sierra extended cab can be found on the vehicle's Service Parts Identification (SPID) sticker. This sticker is usually located in the glove box or on the driver's side doorjamb. The axle ratio will be listed under the "Rear Axle" section. It will be a number, such as "3.73" or "4.10".