What oil filter are you using? If it is a Fram, there is your problem. Use Motorcraft filters. The Fram filter drains completely after you shut off the engine, so it takes a few seconds for the pump to fill it before throwing oil on the lifters. The motorcraft has a way to not allow the oil to drain out of it when you shut off the engine, so the oil is immediately pumped up to the lifters. If that doesn't work, use a quart of Marvel's Mystery Oil the next time you change the oil. That stuff sticks to the lifters, and helps to lubricate them when the engine is first started. Most additives are snake oil, but that stuff actually works.