Cracks are closer to the cab than the brace. Brace also looks loose on the frame so that might be part of it too.
I was told by an old guy who had done lots of truck frame stretch work, that an insert plate shouldn't get fully welded as it makes a place for flex between the two pieces of steel. He told me how C channel frames flex in ways that may be difficult to fully understand and too much rigidity can cause problems. He also showed me what to do when I shortened my '70, which so far has not given me any problems, while we were stretching and inserring a Freightliner to 300" WB.Obviously we stitch welded the repair plate according to the instructions, but does anyone know the reasoning behind not fully welding the perimeter of the patch piece?
I mean MAW....lol, that is a can of worms I am not ready to open just yet. I do plan a cage this summer, so hopefully that will do what I need to stiffen things up.Time to box it?I mean MAW....

Yeah, I could keep a whole pile of them in the blazer and see how many of them I could bend at BB before @ktmoutfront and @Bent77 kicked me off the trails.You should keep the angle iron. Start a new trend.