Hey guys looking for some exhaust help. I have an '07 Screw KR with the 5.4L. It's a daily driver and family hauler and pulls trailers often.And have been doing a lot of reading of past threads and watching lots of videos and came to the conclusion that 2.5" siso will give me the most torque. I installed a Borla #40665 and it's not quite as loud or deep as I'd like.

I was wondering what do you guys have?
Is there something I can do with my existing muffler to to deepen the sound?
Would 2.5"/2.5" SIDO produce better tone and keep similar torque?
Should I be hunting for a different siso muffler?