If you are getting excessive front end rise then you need to either take up some more links in the chains or tilt the hitch head rearward some more or both.
No need for a new shank if your present one will allow you to level the trailer by dropping one hole.
The position of the hitch head on the shank is what is used to level the trailer. The tilt of the hitch head is what levels the WD bars.
The number of chain links used under tension is what distributes the weight. These things are all inter related and changing one will change the other. You need to experiement to see which gives the best result for your rig.
You might also give a good long look at
this thread that explains, in detail, how to set up your hitch.
Hope this helps you out a bit. :)
Barney
