The front I *believe* they are 18 (as in metric), cant remember if the rear bolt is a touch smaller or not. If you are in the states, you likely wont be able to acquire them very easily (metric stuff), but the ford dealership will have them for 15 bucks a pop or something :wtf:.
Whatever the front is (18, but it may have been 19...) anyways its the metric size *just* smaller than 3/4; so I bought a 3/4 inch drill bit instead, and ran it through the leaf string eyelet. It shaves a just a pubic hair off all around, and allows a 3/4 inch bolt to go through. Then just make sure you're RSK holes are made to 3/4 inch and you're off to the races. (I recommend a step style drill bit for making the RSK holes bigger, sometimes a normal 3/4 inch drill bit will 'bite' and kinda oblong' the hole..)