I had a similar installation that went well. It was a American Standard Serin 60x32X?? not sure of depth offhand but quite a bit deeper than 14", going into the back alcove wall of a 5' wide room. Brought it through the door on end, and rotating it down into position was tight but manageable; keep in mind the width of the actual tub is a lot less than 60" underneath the top edging and it is sloped, so that does give a lot of leeway to make the rotation. If you have a design drawing that shows the profile of the tub, you could try cutting out a paper template and doing the rotation "on paper" to see if it will fit. Like you I didn't have any finish walls on the studs so I had that extra inch or so to work with; that probably made a big difference too.