The car is on jack stands since the engine has been pulled.The transmission is in the car. I normally drop the cross member (the cross member is supported with jack stands and let the engine rest on the mounts, at the lowest point possible. It makes aligning the transmission easy. Then I drop the tranny mount bracket and put the transmission bolts in with an air gun with out tightening them to speed up the process. Then I torque to the spec with hand tools, no air guns.