For guys trying to match up different exhaust componnents. I hope this helps. Ichiba Dp- Full 3" internal diameter-304 stainless-comes with a 1 yr warranty. Fits perfectly, clears acd.
Topspeed testpipe-Full 3" internal diameter-304 stainless-quality piece.
Jic 505sus non-resonated- It does taper to about 2.9" where it meets the testpipe. No leaks so far, fingers crossed. Choosing a catback was a big decision for me as it is for everyone. It is very easy to make an Evo sound bad. I could not be happier with this exhaust. It is loud but also very deep, not raspy or obnoxious at all.