I need to replace my muffler on my 60mm Apexi N1 cat back on my 99-00 civic. I know they make a 60mm and 80mm Apexi N1 universal. I would like to gain alittle if possible so I was curious as to how if it would be possible to run my 60mm piping into the 80mm inlet universal muffler. If it would work would it hurt me or help me ?