[72kool]

as others have said, brand quality makes the biggest difference in how long they last. While you can use them in your exhaust system, im not sure the need you would have for them on your truck. the reason they exist and are used is for side mounted engines on fwd vehicles. the idea is that engines rock side to side under acceleration and a solid exhaust system would break over time or the first time you floored it depending on the vehicle. These flex pipes allow the engine to move while limiting movement of the exhaust system. On a rear wheel drive vehicle like our trucks, rubber lined steel hangers are more than efficient in allowing the needed flexibility.