I have a 2.93 with the so called non slip slots on my 04 and am not happy with the belt dust. I am going to add the Steeda Auxilary pulley and a std groove 2.93 or 2.8 pulley. What is your real world opinion on the pulley sizes? I will race the car occasionally so ET is important. I have the following mods currently and may add a Cat back when I hear one I like. (I'm leaning towards the Magnaflow) 2.93 upper 65mm BBK TB with matched intake MotoBlue CAI Predator Tune TriAx Shifter Steeda Diff Bushings
Either way you can't go wrong wih the 2.93 or 2.80 . I've got a stock lightning pulley on mine and yet to see any hint of belt dust on mine and I'm still using the stock belt .
Thats why I opted to change the crank pulley instaed.....the aux tensioner should defiantly help though.
I like the 2.8 with the idler pulley rather than the 2.93 with the no slip pulley. No dust, no slip, 1lb more boost.