Rear shocks on 2004 Odyssey

I'd like to get stiffer rear shocks for my 04 Odyssey. It already has the dealer installed towing package. It sags under heavy loads and I haven't towed a boat yet. Dealers show no listing beyond stock.

Any suggestions?

streakr

I'd like to get stiffer rear shocks for my 04 Odyssey. It already has the dealer installed towing package. It sags under heavy loads and I haven't towed a boat yet.

Same as my 2003- I understand the 2002 Ody springs are a little stiffer than the 2003/4 springs.

The problem isn't shocks - they stop bounce (which there is also too much of). I have thought about using "helper springs" to get rid of the sag under load, but really I want to stiffen the shocks and springs together. I still have this bookmark around for an example of Helper Springs:
http://www.airliftcompany.com/al1000.htm

I am not towing anything yet, so I haven't rushed out and done anything about it yet beyond think about it.