Placing exhaust pipes

[Dreaminator]

We are thinking about running the exhaust back from hedder collectors over the frame rails ( we'll oval them there) and back outside the rails. We will bend 2 1/2 pipe, notch the bottom of the cab box a little and place the Flowmasters vertical. Has anyone else done that? If so, do the mufflers run hot enough to damage the paint? thanks for the thought.