I think you have located the problem. The issue is to repair it and not have it repeated. That is why I would locate GOOD a V8 K-Frame and start putting things back together. I know that your K-Frame could be welded and it might work. Myself, I have a buddy that owns a company that builds scales for loaded semi trucks to weigh on. He is a certified oil feild pipeline welder and I still wouldn't use that K-Frame if he welded it. That is my opinion because I would worry about if the hole was welded where it needed to be and if there was metal fatigue or a twist in the K-Frame.
