Add a scoop of ground beef to the center of the large flour tortillas about the size of the tostada. Drizzle cheese sauce over each, then place a tostada shell on top. Spread sour cream over each shell, then top with lettuce, tomato, and cheeses. Place a street taco on top and tightly fold edges of large tortilla toward the center, creating pleats. Quickly invert Crunchwraps so pleats are on the bottom and they stay together.
