Bring a large pot of salted water to a boil and cook the pasta according to package directions. Drain and rinse with cold water so it cools completely, then set aside.
In a skillet over medium heat, cook the ground beef until fully browned. Season with salt and pepper, drain excess grease, and let it cool slightly.
In a small bowl, whisk together the mayonnaise, ketchup, mustard, pickle relish, vinegar, sugar, salt, and pepper until smooth and creamy. Taste and adjust as needed.
In a large bowl, combine the cooled pasta, ground beef, cheddar cheese, pickles, red onion, and tomatoes. Pour the dressing over the top and gently toss until everything is evenly coated.
Fold in the shredded lettuce just before serving so it stays crisp. Chill for at least 30 minutes for the flavors to really come together.
