The first order of business is in the title to this response.
With your Buick, you should have had the rear wheels off of the ground, and then pulled back the rear end (using a come-along or some such device) until the torque tube was clear of the transmission.
If you want to ever take a ride, you will need to use this procedure to reassemble the drive train. Did you damage things when the torque tube hit the floor boards? Probably not, but look it over carefully for any appearant damage before reassembling.