lance camper porpoising and tires cupping

thanks grit dog. i do realize the issues are unrelated, i guess i should have posted them separately. i will have the ball joints checked when i get an alignment done when i get new tires. I have only put 15,000 miles on the truck in 10 years, and yes over those 15,000 i am guilty of not rotating enough. The tires had only 15,000 left on them when i bought the truck, and now they are due. they are toyo open country MT. I did look under the truck since I posted, and the anti-sway bar links are popped and leaking, so i'll be attending to the front end a lot here soon, just wanted to make sure i attend to all issues, that's why i posted these questions.