I've got a Granby so I can't give you the measurment. But, tell us what you are trying to accomplish, do you want the measurment from the inside or out.We need more info.
I've gathered from photo's and such that in a normal configuration there is a propane box housing the propane tank located in the cabinet (looks to be under the stove). I'm wondering what the dimension on the inside of the camper is from the front wall of the camper to the edge of this box that faces the front wall. IE if you cut down the cabinet length with out moving the propane box (forget about the water tank for now) how far back could you move it till it was right up against the box, and thus how much of a gap would be left between the side of the cabinet and front of the truck?
Or if I'm off on the assumption on where the propane box in a stock eagle configuration that has a fridge in it let me know.