I ended up using the home made bracket that came with my 250, here's a pic of it, it is using the universal adjusters welded to metal plates. You will notice that in the mid 70's they added the two bolts at the bottom of the block. My 75 Nova 250 that I just pulled out had them, and the 72 Truck block does not have the holes in the block. I guess the engineers might have had some problems and added it for additional support. I hope I am fine since I can't bolt up the lower support now. I was thinking about adding an additional section behind it similar to the old air bracket for more stability.
