3.7 Ford Cyclone V6 red line?

[shadow0460]

Just as it says on the box, does anyone know the red line on a 2013 3.7 liter Ford V6? Tach says 7,000 with no redline, I've read anywhere from 6,250 to 8,250. It's tuned and the red line set in the tune may not be accurate.
The vehicle is a very basic F-150.