I have a 65 tradewid double rear bath.when I installed a new floor in the
bath I replaced the black tank with a tank for both black and gray water.I
fabricated the tank to fit between the frame rails and dived it so one end is gray
and has its own dump valve.the plumong is in the bumper compartment I made both
the bumper compartment and tamk 8in deep the tank is 24in Xthe distance
between the frame rails .It is devideded very close to the toilet. the tenk is
bonded to the floor. works for me but trook a lot of engineering to pull it off.
Jim Smith