Look like you have more work ahead of you then I do. I am bringing my engine over in a couple of hours !
When it came to the cross member under my '72, I had a real project on my hands. I spent a lot of time under my Gremlin trying to make a factory cross member work. I tried both pairs of holes to get the mount in a position I needed to mount the TH400. I even tried turning the cross member around to get it to line up. It just didn't happen. I ended up fabricating my own rear cross member.
I haven't done anything about my speedo cable yet. I'll have to find a cable that mates my speedo to the TH400.
Rick
Back to the Home of the AMC Gremlin