Bring a large pot of salted water to a boil. Add the pasta and cook according to the package instructions until al dente. Drain and rinse under cold water to cool. Set aside.
In a large bowl, whisk together the mayonnaise, sour cream, pickle juice, fresh dill, garlic powder, salt, and pepper until well combined.
Add the cooked pasta, chopped dill pickles, red onion, cheddar cheese, and sliced black olives (if using) to the bowl with the dressing. Toss until all the ingredients are evenly coated.
Cover the salad and refrigerate for at least 1 hour before serving to allow the flavors to meld.
