Indexing changeover mechanism for use with a plurality of integrated towing accessories

An indexing block positioned within the receiver hitch and connected to a tri-ball block having a plurality of towing accessories (e.g., different sized hitch balls, pintles, hooks, etc.) on its separate, exterior facings. A biasing member and lock cooperate with an internal, coaxial plunger, thereby allowing for selective rotation of the tri-block relative to the indexing block, without the need to completely remove the assembly from the hitch receiver itself. Ball bearings fitted within the indexing block facilitate movement of the plunger and tri-block relative to the indexing block when the assembly is being rotated to position a new towing accessory in its desired place.