If you want to keep it quiet do NOT put 4” delete tips on! I took the 3” stainless works delete tips off and put the stock res tips back on because the SW tips were god awful loud. I can’t even imagine how loud the 4” delete tips are. As far as mufflers I can’t speak of the Ultraflows, but I just put Quietflow SS mufflers on my truck with 3” dual exhaust and it super quiet, even with 3” duals. I love it!
You "feel" the difference because you want to "feel" the difference. Since you just spent money on the upgrade you "have" to feel the difference
I'm looking to eliminate the double pump process I have to follow right now to get the pedal hard
2004 300A Procharger #0010 D1X
2003 300A Procharger #0017 D1SC (SOLD. Last I heard, it was in Washington State)