I'm selling a guy a Mac catback, just the last couple feet of piping and the tailpipes (for an IRS), and in place of the rest of the catback I'm selling him Magnaflow, (mufflers, etc.) I had the Magnaflow catback on my Cobra, but decided I wanted to keep the look of it from the back because I like how it fits. So I had the Magnaflow mufflers and piping before the mufflers (that runs into the H pipe) removed and replaced them with the Mac mufflers and piping that runs into the midpipe. Bottom line, the guy wants to know if he is going to have to have any welding done to make his system work with my Mac catback + Maganflow mufflers, or if it will just bolt on. Reason I need to know is because it will affect how much I sell it to him for, or if he will even buy it at all.