The Ford V10 will give you plenty of pull with the Saturn. The mountains all along the Rockies just require a change in thinking while you drive. The trip and the scenery are all part of the vacation, so slow down and enjoy the view. Watch the RPMs (not closely, just be aware). When going down hill don't let the rig accelerate with gravity, rather keep your speed comfortable, I like 50mph on the downgrades, so I can maintain braking control. I do remember my first trepidations traveling through Colorado...they were unfounded.
Happy Trails