Honestly i think they are bogus for ls motors.
But...... i did buy one LoL. I got it used for $20. The guy i bought it from said it made 6hp thru the whole rpm range. For the $20 i was like screw it lets see if this thing works.
Havent installed it yet. When i get my tune im gonna have the tuner get the car dialed in on the dyno. Then add this power wedge and see if it makes any more power...
2006 GTO M6
Motor - Stock with Vararam
Bunch of suspension
Bunch of brakes
12.81 @ 110.6 2.03 60'