Kevin - depending on where you are for the tanks. I got my grey water
tank from Pelland/All Rite in Arnold, CA and have the fresh and black
on order to. I am putting the black underneath in the next to the
rear-most opening of the frame - it still gives me enough clearance.
The grey is going just aft of the axle (single, straight axle on a 17
ft trailer), again slung under the floor. The fresh is inside under the
bed (in the very front of the trailer). Since mine is a complete
rebuild, it's actually simpler I would think since I can put the tanks
pretty much wherever I want them - given the size and shape of the
frame.
Also, if you've got the shell off, now's your chance to lay the
trailer out the way you want it instead of the way the factory did it -
personalized rather than for the masses.
Jo Ann