New TV Old FW bed rail clearance solutions

[GoFishing]

I have a 2010 Silverado HD 3500 long bed and a 2003 fifth wheel that has had axles flipped (and is as high profile that I think is safe). I am still having issues with clearance (4inches). I have adjusted kingpin/hitch and am not comfortable with a nose up position. I have spent several days searching solutions for this. I would prefer not to lower the truck if possible.(but will as last resort) Not sure what size blocks are in back suspension but I have read newer trucks have higher bed rails vs higher suspension. My question is has anyone considered placing weights in the truck bed (I am thinking about a truck water caddy and also attempting to increase pin weight inside the FW to help level rig and achieve more clearance by increasing the "sag" in TV? Hope that makes sense. My hope is with the extra weight it will result in a nose down then I can adjust my hitch/king pin to level. Any thoughts or help would be appreciated.

[N-Trouble]

I'm not a fan of carrying around extra dead weight simply for the purpose of lowering ride height. A better option would be to install a set of drop shackles on the back leafs. Sulastic shackles tend to squat more as well when loaded and improve ride when unloaded. Another option would be lower profile tires on the truck. Doesn't sound like there is much you can do with the trailer since the axles have already been flipped.