Pypes catted X, 12" resonators, SLP LM. From the video the catted x doesn't sound that much different than the prochamber w/hi-flows.
YouTube - 06 Mustang GT, Pypes Catted X, 12" Resonators, SLP LM
YouTube - 06 Mustang GT, Pypes Catted X, 12" Resonators, SLP LM