Sorry the information that I gave you was for a Shorty Antenna purchased from American Muscle. At the Steeda site, you use the existing bottom for the top you purchased.
2013 Silver V6 Premium, Ford Racing Handling Package, MGP Black Caliper Covers, Airaid CAI, Bama Tuner, BBK Catted X-Pipes, Corsa Sport Axle-Back Exhaust, Alum One Piece Driveshaft, BBK Ceramic Shorties, Whiteline Adj. UCA, Whiteling ADJ. Lower Control Arms, Whiteline Adj. Pan Hard Bar, Upgraded Rotors (Cross Cut and Drilled), Ceramic Pads, J&M Stainless Steel Brake Lines (Front and Back), 18" Staggered Chrome Bullitts, MMD Eleanor Side Scoops, Side Scoops, Roush Front and Lower Grilles and Super Snake Stripes.