I'm also coming off of a shoulder injury. I would recommend stretching combined with specific shoulder strengthening exercises and LIGHT versions of these exercises you are looking at performing in the long term. Just stretching for a week and then going and deadlifting 400 lbs is not going to be any better for your shoulder than just deadlifting the 400 lbs.
On the other hand, stretching and strengthening (in my case, external rotation specifically) and deadlifting 150 or 200 lbs and gradually working your way up to 400 lbs would be a much better plan. Even if the 200 lbs feels light to you, remember that it's all about making sure that shoulder doesn't bust again.