Bought for my 03 Silverado with 3" inlet and outlet. It didn't fit my truck, someone said it would fit but it was impossible to lose it. It was common Thinking of using exhaust clamps and that didn't work either due to the size I ordered.As a result welded with spacers.When I got it I just replaced the old one with this one and it sounds good.Low sound is loudest at 2000rpm .Adds extra sound to your truck without braking.