This may help:

If you do end up needing to shorten the tube, instead of just trimming off the excess, take a section out of the pipe between the beaded end and the first bend. You can then weld the remaining parts back together. This will enable you to retain the bead on the end so the hose will not slip off under boost. Don't attempt to run without this bead, as the hose will continue to pop off at the most inconvenient times (like when you are waxing a Camaro).

You can also just cut off the excess and restore the tube bead by welding a bead all the way around the tube at its end. Now, the weld bead will retain the hose connection.

My preference is the first way.