A simple solution would be to just lower the floor of course, the way it is in the picture below, but I love the way the floor is so high up inside the body and the interesting details the bottom reveals about the inside. If anyone else wanna go geeky about this with me I'd love to hear your thoughts. 
This is the canon interior:
Here's a rendering that was made by someone following the models from ESB very carefully:
As you can see the floor is very high up in the body and the various things on the underside takes up a lot of space below it.
Here's a better picture of the underside. It's interesting how the original design makes it seem like a long round corridor goes all the way from the neck and through the entire the body of the beast, with perhaps the square part in the middle being some kind of engine room, as it's connected to the legs.
This is the canon interior:
Here's a rendering that was made by someone following the models from ESB very carefully:
As you can see the floor is very high up in the body and the various things on the underside takes up a lot of space below it.
Here's a better picture of the underside. It's interesting how the original design makes it seem like a long round corridor goes all the way from the neck and through the entire the body of the beast, with perhaps the square part in the middle being some kind of engine room, as it's connected to the legs.