Hi, I am about to purchase a 2019 F250 6.7L new. The dealership has added a 6” lift and after market tires and rims. I am purchasing the extended warranty. I was all ready to go then the dealership wanted me to sign a paper that said the truck had been modified and the modifications may void my warranty. They said the parts were all parts approved by Ford. Will this modification done at a dealership really affect my warranty? And if so how could they think I would by and extended one. Thanks for anyone thoughts or advice on this.