03-04 Turbo Whistle

I was wondering if anyone could possibly help. I just bought an 04, and want the awesome turbo whistle that the 03 and 04's have when I do exhaust. I have read that it was only the 03's and early 04's that have that really loud whistle. The ones with only 10 blades on the turbo. My truck has a mfg date of May/04. Would that be considered a late 04, one with 13 blades on the turbo?