Actually yes. The class I'll most likely end up in requires the fuel cell to be mounted flush or below with a 1/8 thick plate bolted to the frame covering it.
As for the batteries I have a trick for that too.
You know the area between the passenger side frame and the quarter panel where the trunk floor extensions go? Well, some measuring shows that I can fit two batteries there? Tops flush with the trunk floor , thus not only offsetting my front to rear weight but helping to offset the driver weight some as well