RealTruck carries a great selection of custom door sills your 1971 GMC C/K Pickup 3500 truck. Shop an excellent selection of door sills you need to upgrade your GMC pickup. RealTruck carries stainless steel, billet aluminum, diamond plate, and illuminated door sills for your 1971 GMC C/K Pickup 3500. We also offer free, fast shipping, and the best customer service you can find. Shop now or give us a call at 877-216-5446.