A method for installing a pre-assembled powerplant and pylon assembly on an aircraft comprises determining a first length of a first link, determining a second length of a second link, determining a first distance occupyable by the first link between the pylon and the aircraft, determining a second distance occupyable by the second link between the pylon and the aircraft, determining a first result by subtracting the first distance from the first length, determining a second result by subtracting the second distance from the second length, and determining a third result by adding the first result and the second result. If the third result is less than or equal to zero, the first link is installed between the pylon and the aircraft before the second link. If the third result is greater than zero, the second link is installed between the pylon and the aircraft before the first link.