Jefferson, tubs are an item that should be purchased from MH supply,and here is why. Standard residential tubs measure 60" in length. MH tubs measure 54" long. Using the same size replacement will save 10’s of manhours over converting and all the associated modifications. ABS is the most common MH size tub, and while they are not built for the ages, their flexible characteristics make them MUCH easier to get in bathroom than a more durable, but rigid fiberglass tub.