Abstract: The present invention is a generator set tank and enclosure that includes a number of adjustable generator support assemblies that enable the tank and enclosure to be configured for use with generators of various sizes. The support assemblies include mounting channels configured to be secured to the tank in a variety of locations, and each channel includes a number of support platforms therein which can be adjustably positioned on the channels to further adjust the configuration of the support assemblies. Also, the tank and enclosure are configured with multiple fittings, attachments, and access points in order to enable both the tank and enclosure to be fully customizable for use with generators of various sizes.