Go ahead, if you want to be like the tuner car group, of whom us men drive our trucks over.
My advice, get that thought out of your head, cause it's a bad idea, it will allow water to get up inside and cause it to rust from the inside out.
But if you want a real man's sound, cut out your muffler and replace it with more exhaust pipe. Leave the cat on though, as you won't pass emissions without it.
But your truck will be louder and meaner than any muffler you can buy. And in my experience, you will noticeably gain more torque, and maybe a couple hp.