My bad...
I thought you had them installed already...
You do not want to use the open hole! I tried it with washers and it just BENT the fender lip!
I used the fender bolt hole just behind it (towards firewall side) It just needed to be enlarged a little & I also put a nut on the stud for insurance...
My struts measure 16" in length when extended and holding the hood up. They hold it considerably higher then the stock prop rod. (you've seen it)
I also used 8mm ball studs on all 4 sides and my struts have metal retaining clips to hold them to the studs!
Be VERY careful tapping the hood mounting hole. You can easily wallow out the hole too big... Use only a high Quality tap! I flattened 2 cheap ones (generic specials - I returned them of course

) before I got off my wallet and bought a quality tap.