actually 2.5 with a glass pack is still considered overkill(too free flowing). 2.25 with a single chamber no cat is equivalent to what you used. to gain the best compremise of torque; its a header without cat straight back 2.25in pipe with a 2 chamber or equivalent muffler. if you want a clean crisp sound, try a flowmaster delta series. if you want a deep sound, go with a MAC muffler.
