Is there any difference in length between the two B-pipes?

 

I would say that the coupe one is shorter according to the diagram in http://www.hondaautomotivepart...+PIPE

 

yes, the hatch's b-pipe is longer because the cat is on the exhaust manifold. The coupes the cat is underneath the so the b-pipe is shorter. You can use a coupes b-pipe on a hatch but you have to move the cat underneath the car or get a test pipe.

 

Even when you compare the DX coupe (which had the cat in the same spot as the hatches) the B pipe is a different setup completely. the hatch has a shorter wheelbase than the 2/4 doors do. So, in a nutshell, it is not a direct bolt on. You can use a coupe B pipe but you'd have to cut and weld on it to make it fit correctly.