Abstract: A tank valve system comprises a main valve body, an overfill protection device (OPD), a gauge drive apparatus and a fuel level indicator. The OPD and gauge drive apparatus are configured to both be inserted through a narrow neck of a fuel storage tank prior to connecting the valve body to the neck. The valve body includes a primary fuel channel and a shuttle interface channel. The OPD includes an overfill float driving an overfill shutoff valve for controlling fluid flow from the primary channel into the tank. The gauge drive apparatus includes a gauge float, a shuttle, and an elongated extension body. The gauge float is movable with respect to the extension body between an uppermost position and a lowermost position, thereby driving the shuttle. The shuttle has a gauge actuation portion transportable within the shuttle interface channel to thereby actuate the fuel level indicator.