We recommend that you always install the used Cummins generator on a concrete floor. This will help with noise reduction (more on that in a moment), as well as give your generator optimal power.
Wherever you'd like to install it, make sure to pour a concrete base over the top of the floor. Embed it with an anchor bolt and make sure that the concrete is 6 inches or higher from the base of the floor.
Make sure that you take the time to read the manufacturer's installation instructions and follow them to a "T".