I'm working on converting my 6BTA (with a water to air aftercooler) from a high mount rear exhaust to a high mount front exhaust. I ordered the appropriate cross over tube that is listed in my parts book, but when it showed up, the inlet measured 2". The bummer is that the output from my turbo compressor is 2. 5". Does anyone know what the correct part number is for the high mount front exhaust 2. 5" cross over tube? Or, does anyone know of a friendly establishment that could help me out? Cummins N-power gave me the run around and can't do much without a S/N and CPL. 
Thanks!

Thanks!