Changed my mind and need help!

before I wanted to get the RS*R universal muffler, but now I came across the 5ZIGEN FireBall universal muffler. Now my question is would I have to get a new Catalytic Converter?? the site says Note: 60.5mm Diameter Inlet. SO i was just woundering cause I have a guy doing custom pipeing for my new muffler. this might be a dumb question, but I just wanted to ask you guys before I go ahead a do this. Thanks for the advice!!

no you dont have to change the cat. they will weld u a new rear section if u tell them to.

http://www.g2ic.com/forums/showthread.php?t=118181