Trans-Dapt Performance Products 4134 Differential Cover Aluminum Features: Differential Cover; Aluminum Height: 6.50 Width: 15.25 Length: 15.25 Weight: 5.48 lbs Fitment: 1981/GMC/K1500/Sierra Grande Standard Cab Pickup 2-Door/5.7L 350Cu. In. V8 GAS OHV Naturally Aspirated::8.875 in. (12 Bolt), Rear^^1981/GMC/K1500/Sierra Grande Standard Cab Pickup 2-Door/5.0L 305Cu. In. V8 GAS OHV Naturally Aspirated::8.875 in. (12 Bolt), Rear^^1981/GMC/K1500/Sierra Grande Standard Cab Pickup 2-Door/4.1L 250Cu. In. l6 GAS OHV Naturally Aspirated::8.875 in. (12 Bolt), Rear^^1981/GMC/K1500/Sierra Classic Standard Cab Pickup 2-Door/5.7L 350Cu. In. V8 GAS OHV Naturally Aspirated::8.875 in. (12 Bolt), Rear^^1981/GMC/K1500/Sierra Classic Standard Cab Pickup 2-Door/5.0L 305Cu. In. V8 GAS OHV Naturally Aspirated::8.875 in. (12 Bolt), Rear^^1981/GMC/K1500/Sierra Classic Standard Cab Pickup 2-Door/4.1L 250...