I'll put my 2 cents in on this one real fast even know its getting a bit older.
I have a 2000 gt vert if some go fast parts and last year decided to do headers, My setup all said and done ended up being
bbk lt headers/ o/r X/ and I bought the slp lm1's for the simple fact they were 150 bucks total for both brand new and welded them into an old
flowmaster 40 catback system. The result was the most obnoxiously loud car I have ever been around, I mean (and im being honest here) There was almost no difference from running it up the street open headers then with the catback instaled.
That being said it wasen't raspy just plain loud... 5 noise violation tickets later I find myself now with a pair of flows 40's back on the car lol