The tank is not a simple rectangular cube. It has some "high rise" at a couple of places. The tank is used on gassers as well and gasoline needs more expansion room or so the "thinking" goes.
This post from DTR shows the what and how. Raising the bed is just as easy according to some as dropping the tank. With my topper, etc, it'll have to be the tank drop.
For us, it is nice to have a few more gallons, so to speak, but the tank fill
accuracy ought to be much better. I like to let the nozzle run to first click off for consistency sake and this mod ought to make this a bit better. Figure two gallons more, and maybe three in comparison to a fast fill.
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