for the top mount struts, there were 2 different designs for the struts. first, there was the one that just had a big "bump" where the hole was ( this is not the preferred one). the preferred one was, and is, thicker all the full length of the strut (much safer). as far as the holes, there is a straight hole which is the preferred one, and there is a tapered one. the tapered one does it's job, but, there is a tapered sleeve that fits into the hole and this sleeve is split vertically to allow the tapered sissy bar to fit into the hole. BUT, this one has been known to crack the strut if the sleeve is put into the hole with the split facing outward and you tighten the screw into the sissy bar too tight. this was the reason for the redesign to the thicker struts with the straight holes and sissy bar ends. hope this is not too confusing.