Originally Posted by Rocky
4 if you know what you are doing. 12 if you don't.
Yes but this is a professional shop. They have a lift and transmission jacks and air tool and should know what they are doing. Four hours is a reasonable time and it can be done faster.
In the case of this thread the op paid to have a used case purchased and rebuilt before install. Manually rebuilding a box is time consuming so the 12 hours labour charge is not put of the question.
$2400 to purchase a used box. Rebuild it and install it is a bit high, but not crazy.