I am trying to replace an one piece old shower tub with surround because the bottom is cracked and the color is faded almond. Also I am trying to convert the separate hot/cold into a single. So the old tub has to go. The problem is that all standard tubs I looked at are 60" (5') where my bathroom is exactly 57" wall to wall. I have no idea why or even how the old tub was put in. Is there a trick to install a standard 60" tub into a 57" bathroom or do I need to special order one that fits?