Just buy the right length magnaflow magnapack mufflers and clamp them on, or are the pipes different?
I don't think it will fit without bending the exhaust pipes. The regular magnaflow mufflers are oval and have and offset in/out. The magnapacks are straight through mufflers.
I had mine done at an exhaust shop because the pipes are a bit different due to the offset mufflers on the regular magnaflow system.
From my understanding, the tailpipes are the exact same, it is just the flow tubes (the tubes between the h-pipe and muffler) are bent a little differently to get the round mufflers to match up with the tailpipes.