Strengthen 2005 rear suspension?

Hi. Hoping some of you can help.

I have a 2005 XLT V6. The rear end sags more than I'd like when towing my boat. Approximate tongue weight of the boat is 320 lbs. If I can't get the tongue weight reduced I'd like to "beef up" the rear suspension so it doesn't sag as much when towing the boat.

I called a suspension shop and they said there are variable springs (or variable resistance? I think that is what he called them) I could have put in for about $500 ($300 labor and $200 parts).

I don't think I want a lift kit.

Any other suggestions?

 

[MountaineerGreen]

A pair of variable rate springs would work fine- if the right rate is used, you shouldn't notice a difference in ride, the more they are compressed, the stiffer they get. But, I have never seen a variable rate spring kit for your model, I'd be wary of what they install.

 

[LVmounty]

Did you end up getting those springs on?