@Grandvanyon, I hope my experience here gives you a little comfort on top of all of the other people who have said not to worry about it. I've had several 5.4 vans. I have worked on numerous other ones for members here, friends, etc. I also worked for a company for 25 years that has thousands of them on the road delivering packages and I drove probably 50 different ones in my tenure there.
I have never before this day heard of a PCM going bad in a Ford gas van. These vans are incredibly robust. Check the stuff Scalf and others have recommended above and enjoy your trip!