First, yes, you should use the WD bars even if the truck does not squat when hooked up. Your receiver has a weight carrying limit without them and I am pretty sure your tongue weight would exceed that limit without using them.
Also, using the WD bars will normally give you a better ride and better steering because they restore the weight taken off the trucks front axle when you hook up the trailer.
Take a look at
this thread, which is stuck at the top of this forum, for help in setting up your hitch correctly.
There is also another thread up there that explains how a WD hitch works. You might want to read at least the first post in that thread.
Barney
