4" PERF SYS W DLSS 2.5 C O & RR DLSS 2015 20 FORD F150 4WD. 1977 pontiac firebird esprit esi5971071 The large single mandrel bent tailpipe 1996 ford mustang svt cobra esi2623047 The large single mandrel bent tailpipe exits behind the passenger side rear tire and is finished off with a large 4 This intake system moves the air filter away from the stuffy engine compartment so cooler air can be circulated into the engine for an increase in power The Fabtech ductile iron steering knuckles retain the stock track width keeping the tires under the fender for a clean appearance The Performance System features Dirt Logic Stainless Steel 2