X-pipe with stock mufflers??

Hey I'm new here and just bought my Mustang a few weeks ago. I want it to be louder and my friend has a Bassani off road X-pipe that he is willing to sell me for $100 so I couldn't resist. My MIL eliminators will be here Wednesday from Jegs and I want to know if I can go ahead and put on my X-pipe with all of the exhaust stock for now? I will be replacing everything with 2.5" piping and Flowmaster 40 series eventually but not yet. Any help would be appreciated.

Also this icon is freakin' awesome!!

Alrighty thanks. I'm hoping it won't hurt my performance and it'll be a nice deep sound. Grrr Jegs needs to hurry.