727 been sitting.

If it's been sitting in a clean dry place then just sitting there shouldn't bother it. You might want to pull the pan off & take a look inside to be sure & see if there are any signs of damage, rust, bugs, mice(you'd be surprised) and of course any metal debris. If you trust the history of it & all looks good, run it & see how it is. Throw a new filter & pan gasket on it while you're in there too.