On the trunion and round bar type WDH's, the unloaded ball height is significant. The steps to set up an equalizer or E2 are well documented on the vendors site so they might be for your hitch. If the prospective owner has doubts, negotiate the sale of the TT without the WDH and let him buy his own and have it professionally installed.
I transferred the WHD from my old 1500 to my current 2500HD and the ball needed to be lowered. I'm on the last hole of an drop shank. If I had to drop the ball more, I'd be looking at a $100 shank.