Great question. I ordered the truck on May 4th. Came home and bought the Borla, that was in my garage two weeks later waiting for the truck. Then, about a week before the truck got here, I heard the American Racing Headers and had to get them. I called American Racing the next day and picked their brain a bit by speaking with the owner, Anthony. I ordered them and they came in after the truck was at the dealer about a day. I brought everything down to my dealer and they installed the CAI, Borla and the Headers on and it was ready when I took delivery. I start it and my face hurts from smiling.