Abstract: A pin box for connecting a trailer to a tow vehicle includes a hollow receiver tube attached to a pair of support beams positioned on opposite sides of the receiver tube. A forward mounting bracket for attaching the pin box to a frame of the trailer is disposed between the two support beams. The mounting bracket is fixedly attached to both support beams. A second mounting bracket is attached to the ends of the support beams opposite the receiver tube. The pin box also includes a hitch connector that is slideably engageable with the receiver tube. The hitch connector may be positioned within the receiver tube at a plurality of discrete predetermined locations. An attaching means is provided for securing the hitch connector to the receiver tube at each of the predetermined locations. The hitch connector may be configured to include a king pin connector or a gooseneck connector. Differently configured hitch connectors may be interchangeably connected to the receiver tube.