IMO, an engine stand is a better way to break in an engine when using a WOT break-in method. You have a controlled load, the engine has no problems getting up to temp and you don't have to worry about putting a strain on any drive train parts. Yes, you do have to buy the stand (and possibly the prop starter, depending how comfortable you are using the chicken stick method), but it just seems to make life easier.

Just my 2 cents..