[joe_padavano]

First, these frames are mild steel and a properly done weld will be at least as strong as the parent metal. The crack-stopper drilled holes are a must if the crack is closed ended. If it goes all the way to an edge, you need to take some additional precautions. One consideration is the undercut you would get at the edge of a frame flange. GM recommends using a run-off tab against the edge of the flange and continuing the weld onto the tab. This gets the start-up or tail-off undercut off the frame and the tab can be ground off later.