4.6l or 5.4l

So I bought a used 2005 mustang gt a while back and I replaced the motor mount and bracket this week . On the passenger side of the engine bracket 1 bolt is off by 1 inch from center to center. I emailed BMR and they asked if it's a 5.4L engine block. Does anyone know how to identify the engine...

So I bought a used 2005 mustang gt a while back and I replaced the motor mount and bracket this week . On the passenger side of the engine bracket 1 bolt is off by 1 inch from center to center. I emailed BMR and they asked if it's a 5.4L engine block. Does anyone know how to identify the engine...