I know its a royal PIA but considering what its gonna cost, you may want to take it out and have a machine shop weld it. I did that on my 72 because somebody had full clamp pressure on something other than paper, and cracked ours. Its still not real pretty but that was a real long time ago and its still working fine.
I had the same worry but the machine shop did a great job, we actually had to have a new end made, pinned and welded to the old one. Even if you get another one, you will still need to set your shims and pressures. Its not hard to do its just a pain.