Is there currently a strike plate and hole in the door jam from an old lock?
Measure the depth of the hole, that will limit the amount of bolt tongue that can be extended into the jam. Extend the dead bolt and mark the tongue with that hole depth. From that mark measure to the center line of the lock set. Assuming there is a gap between the door and the door jam that dimension should give you location to the center of lock set on the door.
If there is not a hole in the door jam to accept the dead bolt. create that hole first so you can determine what you have to work with.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles