Street legal for late-model 5.0L Ford mustangs. 65mm size is ideal for stock manifolds. 70mm is the optimum choice for the Performer 5.0/Performer RPM 5.0 EFI intake and The Total Power Package. 75mm is intended for more radical engine combinations and requires port matching to fit most manifolds. 1986-93 Throttle Bodies must be used with matching EGR Plates. Gaskets are included.