Borla 21-23 Ford Tremor 3.5L V6 AT 4WD 4DR CC SB 3in ATAK Mid-Section ExhaustNOT Compatible with the 3. 5L PowerBoost. Fits Models With Bumper Cutouts (Notches). For models WITHOUT bumper cutouts, use one of our standard Cat Back systems like 140867. This Mid Section Muffler Assembly features 3" diameter pipes and the aggressive ATAK sound with no drone inside the vehicle. It fits with either BORLA tail pipes 60640, 60640BC, or 60640CFBA, or the Original Equipment (O. E.) tail pipes. It features our Polyphonic Harmonizer