I have a suspension arm that I am rebuilding, the main reason is to make it adjustable in length, and the other is to replace the ball joint. The original equipment is a standard automotive ball joint, greased and the shaft is 1 piece with the ball. The new setup would use a 5/8 spherical rod end with a hole ID of 15.87mm (.625") I can only use an M12 bolt which would be about 55mm long plus the thread. I would need to use 2x stainless steel spacers to mimic the taper on the ball joint stud, and also to space the head of the nut out so that it doesnt interfere with misalignment, it would only be spaced about 3mm or so. My question is, will this setup be as strong, stronger or weaker than the original setup? To me it looks weaker but I am no expert. Any advice on how to mkae it better, or advice on what can be changed etc. The Rod end is Chromeolly The spacers are stainless (I can use other materials if need be) The bolt is eitehr 8.8 or 10.9, both are readily available. My next question is, what can be done to stop the bolt undoing over time? Standard they use a cotter pin through a castle nut, and the taper helps it stay in place in one direction. I dont think I can buy an 8.8 or 10.9 bolt that has a hole in t for a cotter pin, so what can i do? Should I use a nyloc nut instead? Locking nuts? Or can i drill a hole in the bolts without effecting strength? The way i see it the hole would be past where the load is, but I am not sure if this is safe. Also are castle nuts even available in a 10.9 grade nut?? Thank you very much for any help you can give My email is email@example.com if you have any other specific questions, bu I will keep an eye on this thread, as I am trying to have these parts made within a week.