RealTruck carries a great selection of custom door sills your 1978 GMC C/K Pickup 1500 truck. Browse a great selection of door sills you need to enhance 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.