Gp, are you saying the existing crossmember does not need to be removed to install an sbc with an automatic? I thought i read somewhere that it needs to be cut out. I saw and like those tube crossmembers to support the back of the tranny. I see they have em for the engine as well.
From what I see, you want to leave this/that. It supports the bell housing before the trany.
I think with a 700R4 you would want that trany bar.