My set screws go all the way through the shaft. It was drilled and longer studs used. Used red loctite on them. That was so I could service them if needed. That part of the shaft has a bunch of room to come out a bit. Not sure on actual measurement ...or if it changed with the airbag column. Mine is an 89. A couple beads of weld would be extra insurance. There's no way I'd use them without drilling a hole to accept the keepers. I even though about having them drilled for a roll pin.