A horizontal support tool for an engine build stand, the horizontal support tool includes a support tube along an axis and a tie shaft between a handle and a puck assembly, said puck assembly including a puck selectively extendable and retractable transverse to the axis in response to rotation of the handle. A method of horizontally assembling a portion of a gas turbine engine including mounting a first module to an engine build stand; installing a horizontal support tool into the first module, the horizontal support tool supported in a spherical bearing supported by the engine build stand; and installing a second module to the first module, the horizontal support tool operable to at least partially support second module.