The Hensley is indifferent to tongue weight in terms of sway control, but I've found towing on the way home with fresh water tank empty (ahead of the axles) and the holding tanks almost full (behind the axles) I get more porpoising than I do on the outbound with full fresh and empty holding tanks.
I agree with JBarca, sometimes it's just the road. Bilsteins will probably help some, but don't expect a magic cure to this one...these problems are unique to the rig/road combo. You many not have an issue on that stretch of I-90 and JBarca may not have an issue n that stretch of I-10, as was stated, sometimes all you can do is slow down.
My Dad used to commute to JFK in a VW Beetle, and on very gusty days he would say, "Sometimes all you can do is put on your blinker."
