Help! Any advice? Changing locations of water tanks

[silver suz]

1971 31' sovereign-We need some suggestions on how to relocate the black water tank, whether to install a grey water tank (none now, but can use old fresh water tank). and where to install the new fresh water tank. We need to order the new black water tank so we can adapt configurations. We are moving the bathroom over the curbside wheel well. Toilet can be either front or aft in bathroom with sink centered on window. Shower will be on other side. the washer/dryer combo (one machine) with be foreward of the bathroom. Kind of across from the sink which is in its usual place by the window aft of the door, a small 4 setting dishwasher will be under/next it. With the hot water heater (undetermined size) next to it, under sink. No stove, no heater, so room under the sink.
Question? the plumbing and slant downwards will change. any problems we should be aware of? Can we move the black water emptying valve forward? with the black water tank? Any hints on where we should put the grey water tank? Presently the plywood floor, black water tank is out to address the rear end droop problem. With 2 widths of plywood flooring gone, do we need to brace the walls with 2" X4"'s? Thank you for any suggestions. Silver suz P.S. older son got some pictures of the trailer on the photo forum.

[thenewkid64]

I would see if you can get the plumbing layouts from 76-78 center bath model. it will show how the valves are located as well as where the tanks are.

In our 77 the bathroom was alongside/on top of/ and a bit behind the curbside wheel well. This left room for the water heater under the sink, and the shower had a built in seat that was over the wheels. The toilet was located as far rearward in the room as possible. It was approx 20 inches back from the rear end of the inside wheel well cover. This made for a huge amount of space across the hall from the bathroom. More than enough for the other appliances you want to install.

Our fresh tank was under the floor right over the axles. The black tank was just aft of the fresh tank. The dump valve had a Loooong rod on it that kept the valve mounted very near the tank. The outlet tube ran across the width of the trailer. The grey tank was located behind the black and fresh, but not all the way to the rear. it also had a Long rod that connected to the dump valve. Just not as long as the black tank rod was

I guess what I am trying to say is to get the tanks mounted where they fit. You can plumb the out put where you need to easier than finding the tanks.