Resonator delete, tip change, questions 08 2.5

[Samtehrani]

Hey, so basically i want some input from other fellow coupe drivers. Im basically deleting my resonator and replacing it with a 12' louvered glasspack (i fk'ed up and bought louvered by accident, oh well its not going in place of my exhaust anyway). Im also getting my tips swapped for some sexy dual tips. Anyway, i just want to know if anyone else has done a resonator delete with a glasspack, if so hows it sound with the stock muffler? Even if you didnt use a glasspack, hows it sound? Do tips make a difference? -----
Second question,
The tips im getting are 3.5inches for each circle, so 7 total inches wide, im guessing i will have to cut my rear diffuser? Anyone have any feedback on that or has anyone done it with that size tips? I thought it looked about big enough but i havent seen the tips in person yet.
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Third thing just kinda want to share, im getting all fhis done by tuesday next week and basically ill see how it sounds, if its not loud to the point i wanted (just want it to sound sporty at times when i want it to be loud/ have a nicer tone) currently it sounds like a fart because i have a small hole in my cat i dont plan on fixing til next emissions. Anyway as i was saying, im going to just put 1 or 2 washers inbetween the muffler flange to hopefully get the roar i want IF its not loud to my liking. I dont wany anything too loud anyway, just something more beefy and a tad bit louder. Anyway thanks