Bought a companion 5th wheel slider and turnover ball B&W and need advice on pivot arms

[JDZieg]

What is the best setting for the pivot arms for a 2018 2500 with 6 1/2 foot bed for the slider using the Companion 5th wheel slider and turnover ball

 

[BossHogg]

My suggestion is to place the pivot arms so the hitch plate's coupler jaws are over the rear axle. As far as height, you typically want between 17 to 19 inches from the truck bed to the top of the hitch plate albeit you will find the final setting once you have the trailer attached. Your goal is for 6 to 8 inches of clearance between the trailer and the top of the bed rails.