agree with above, I worked at a parts store in college, sometimes the replacement parts have a different sized hex on them. As long as they are the same thread and overall length you are fine.
Since it is a ford i have a funny story, I was helping a friend change out the gears in his 98 mustang. We were both working on on taking the axles out and sharing tools since you needed the same for both sides. After getting in an arguement over where the 10mm wrench was at since he had to have used it to remove the brake caliper bolts on his side, we realized that one caliper had no bolts holding it on to the car.
This was a car that ran 11.50 on the motor and 10.60 on the bottle. He had never worked on the rear brakes since he had bought the car two years before that.
It reassured me I do the right thing spending the time to look at every part of a used car after I bring it home. You never know what idiot worked on it before you.