As promised in my currently uploading video (link to follow shortly!) I have removed the exhaust pipes and muffler from the caprice. It took under and hour, though I did have to resort to some sawzall magic near the end. I figure it can just be welded back together when the time comes, so no big stress.
Now all that remains prior to the stretch is to move some cables and pipes, and I think we'll be all set to go!