Are all hi flow cat the same size in lengths? I don't know which cat to get so it will be a perfect fitment for my cat back exhaust? lets say i have a 95 gsr motor in a 99 civic hb, do i get a civic 99 cat or do i get 94-95 gsr cat?

 

not 100% sure but im pretty sure either way theres gonna have to be some custom fabricating. The gsr cat will bolt up to the header but not the exhaust and vice versa.