The info on using the hughes tensioner is correct in the article I posted. Looking at the photo of the slack in that chain you posted. I would say you would need a tensioner with that. I've seen used chains with less slack. Wonder what that thing would look like after a couple miles?
With a chain that bad you would have to allow for 500 mile slack on install when degreeing it. I would be ashamed to post a picture of a new chain with that much slack. Whats with the punched pins on the Chain? Who makes that chain?