i was wondering if the mandrell bends make a big difference than the regular press bent pipes. it seems like the mandrell bends are really hyped up. would i be able to get the same power from a local muffler shop that makes custom systems?

 

How many of your local exhaust shops have dynamometers? They don't test their designs like aftermarket exhaust system companies. Can you get similar performance with crush bends? Yes, but what are the odds that all the bends are in exactly the right place for your truck? How would the installer know?

For the cost of the Magnaflow or Flowmaster pre-bent tailpipes, I see no reason to let a shop "custom bend" some.

 

For ultimate flow design, mandrel bends are the best. Will a giant, stock F-150 pop wheelies with them; NO. You can look at press-bent pipes as an unknown smaller size. Some can be real bad in the tailpipe section contorting the axle.