Hi,
I have a 1987 Astro and have had numerous problems with this over the years. Aparently, a bolt holding the bracket has broken many times causing the braket to break which is very difficult to repair (maybe its difficult to align properly?). I had it welded the first time, but still broke about 1 yr later. Got a new one installed from the dealer. Broke again about 1 1/2 year later. Took it to another mechanic that was recommended and replaced it for a bit over 1/2 the amount the dealership charged. They said that the dealership didn't fix the bolt correctly. Braket broke again about 1 yr later. I just had it welded again since its alot cheaper, and I don't drive it daily anymore, I just use it to haul stuff sometimes. But I notice there is a decrease in power and runs alot rougher (though it could be EGR related - another common problem aparently).
Hopefully you're able to fix it, but for me, its not worth it anymore since it seems nobody can get it right. You might want to inquire if a bolt is causing the braket issues as well. Best of luck.