When you do it, post a clip because I've been curious about doing the same thing to mine. When I got mine it had the Magnapacks installed on it rather than the regular mufflers that come with the kit. I love the exhaust now, but I like to change it up sometimes and the Macs are what I've been thinking about doing for several months.
I honestly can't imagine them sounding any different on Magnaflow piping vs. the pipes that come with Macs kit, so I doubt you'd notice a difference in sound.
How does it sound? I have been wanting to put the magna packs on mine instead of the magnaflow muffler.