currently i have a resonated test pipe, but i really want to get rid of that and get a carsound cat for my LS but i'm not sure what size to get. I'm either going w/a IB modded JG header or Comptech 4-2-1 header. and for my exhaust right now its Apexi N1, but i'm selling that and going w/a OEM ITR catback for a while. Should i go w/a 2.25" or 2.5" Carsound cat?

 

anybody?