Hitch ball mount question

I am currently using a hitch ball mount assembly which came with a previously owned 28-foot 8000 lb + Rockwood trailer.  I am now pulling  an Rpod 181G, and I think my setup is overkill.  For one thing, it is very heavy - I can still lift it, but I'm not getting any younger.  It is also one of the adjustable-height units, which I don't think I need.  I like to remove it whenever I'm not towing, even when at a campground (I keep banging my knees and shins on it).  I am considering purchasing a lighter weight unit, but I am wondering how changing the length of the shank (distance from the receiver to the ball) will affect towing.  Most of the ball mounts I've looked at are considerably shorter than what I am now using.  Is is better to have a shorter or longer shank?

To answer your original question, with a standard hitch the shorter the distance between the receiver and the ball the better because that will shorten the lever arm between the trailer hitch and the tow vehicle rear axle. That lever is trying to rotate the front of your TV upwards, which is putting less weight on the front axle and more on the rear. 

If you're OK without a WDH (and the Silverado should be able to deal with it), then just figure out what amount of drop you need, and get a conventional hitch/ball. Shorter will be better (and without the WDH, it will be lighter).