Bring a large pot of salted water to a boil. Add in the elbow pasta and cook for 7 to 9 minutes until al dente. Drain and rinse under cold water.

In a mixing bowl, combine cooled pasta with half of the dill pickle juice and let sit for 5 minutes. Drain excess juice.

In a separate bowl, whisk together mayonnaise, sour cream, remaining dill pickle juice, Sriracha, and fresh dill. Season with black pepper and salt.

In a large serving bowl, combine flavored pasta, cheddar cheese, sliced dill pickles, chopped onion, and remaining fresh dill. Pour dressing over and toss gently to combine.

Cover and refrigerate for 4 to 6 hours or overnight before serving.