whats is better??

which would give you the most gains in hp and torque…a cutom cat-back exhaust with 2.25’’ piping or a bosal cat-back exhaust with 2’’ piping?? any other mod suggestions are welcome. thanks

normally people go with 2.25 exhaust when they have high comp and cams…

but would a custom exhaust with like a dynomax muffler better then a bosal catback exhaust??