Lift adaptors for the hook-up and towing of heavy vehicles such as buses, coaches and trucks in a damage-free fashion, avoiding the need for pre-picking. The lift adaptors may be mounted to receivers slidable over the underlift crossbar of heavy-duty, underlift-type tow vehicles. An engagement end of the lift adaptors may be secured to the underside portion of a vehicle to be towed, using an eye bracket, apertures or another attachment mechanism. A movable boom may be used to locate the crossbar in a proper position beneath the towed vehicle, enabling engagement to the lift adaptors. The lift adaptors are preferably designed for quick decoupling in the field so that they may be replaced with forks or other hook-up or towing attachment mechanisms.