RealTruck carries a great selection of custom door sills your 1978 GMC C/K Pickup 1500 truck. View the top brands in door sills you need to upgrade your GMC pickup. RealTruck carries stainless steel, billet aluminum, diamond plate, and illuminated door sills for your 1978 GMC C/K Pickup 1500. 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.