
If the clip has been auto stretched by FL it will be perfectly lined up with the grid in the playlist. Pro Default, or Tonal are both good for stretching vocals. FL has a number of high quality stretching methods, which you can flip through while listening. Click the dropdown list in the time stretching section to choose a stretching method. If your vocal clip has tempo embedded, then FL will have already stretched it to match the project tempo (unless you have that option disabled in Options > General settings).

In the audio clip channel settings (SMP tab) you'll see a Time stretching section, with 3 knobs and a dropdown list. I gather you mean changing the speed, while leaving the pitch intact? If so, then yes.
