2001 Spicer/Dana DSP40, Truck Tractor, Front Rears (Tandem Front), Fits to: Peterbilt 379, (Used) 2001 Peterbilt 379, FRONT DIFFERENTIAL GEARS ONLY- Make: Spicer, Model: DSP40, Ratio: 3.90, Capacity: 20,000 Lbs, For more information about this item, give us a call. We ship Worldwide! (CRG HEAVY TRUCK PARTS) 929 W PULASKI HWY ELKTON, MD 21921, Ratio 3.90, Serial# TBD, Truck Year 2001 1XP5DB9XX1N563937