Sounds like you need to change bolt holes to raise the ball. If you got your truck back to Ford’s specs with the chain tension, the only other adjustment is how high the ball sits.
When I changed trucks, I had to move the ball to get the trailer to sit correctly. I like mine a tad nose down. Measuring on the frame, there was about an inch difference. When I set up, I went to a parking lot that was about as level as parking lots get.
The only porpoising I get is on some stretches of concrete highways. Usually a speed adjustment takes care of it.