Run the tail light wires in a protected place, lower the bed on the rails, bolt the bed in position and connect the tail lights are the steps for installing a flatbed on a Dodge truck. Purchase the correct flatbed for the truck model that you are using.
Inspect the wiring running to the back end of the truck. If any wires are on top of the rails, or loose, reroute them inside of the truck bed frame rails to protect them from being crushed or broken by the flatbed.
Measure the flatbed and the rail length from the end of the rail to the back of the cab. The two measurements should match to ensure a proper fit. Lower the bed onto the rails. The bed is too heavy for a single person to maneuver by hand, so additional help is required, or the use of a hoist.
The mounting holes in the frame rail should already be tapped from the manufacturer. Appropriate mounts can be purchased at most auto parts stores in two or four hole configurations. Insert one bolt through the mount and frame rail in each corner, with a washer on both ends. Insert the remaining bolts and tighten all of them with a socket or impact wrench.
Additional mounts can be added, if needed, for stability with different types of loads. Connect the wiring that you ran through the frame rails to the tail lights, and test them.