This may be completely ridiculous, but what would it sound like if you put either a glasspack or resonator after your y pipe possibly in place of the cat and the routed the rest back through a muffler?
Would this sound good or would they just completely counteract each other and sound horrible?

 

i would guess the latter of the two

 

Well what that will do is give the exhaust a more deep and mellow tone to it. It'll get rid of all those high pitch notes. Many imports exhaust systems have a resonator before the muffler. Makes it sound better in my opinoin. Though I have never heard that setup on a V8 though. But I think it would sound just fine. Probably be a bit louder since your getting rid of the cats and putting glasspacks.