Help! I need 3rd member studs!

ive had this problem before too, i took a 3/8 bolt and wrapped saftey wire or some kind of thin wire around the thread and leave an inch or more to hang out, when you install the third member poke the wire threw the hole and hang on to the wire so the bolt dont fall back into the housing, start all your nuts and i used needle nose pliars to hold the bolt and started the nut and tightened it last and it tightened with out a back up wrench and is still holding, if you got a welder tack the bolt into place.