The one I am swapping in my car is from an auto, just swap the flywheel and figure out the turbo oil drain and you are good to go.
It won't necessarily 'harm it', no. The sealant can leak if excessive pressure is put on the oil pan but that should be removed and resealed anyway.
And the automatic block dropped into my car just fine, every bolt fit exactly the same as the original. Pref must be mistaken.