Got to lift the fiver

You can also reverse level the truck. Then add airbags to level the truck after pin weight is added

I helped a buddy lift his 5er. We build a subframe out of box steel 6" tall. (maybe it was 8")
Anyways, we cut off the hangers, welded up the frame extension to the bottom of the existing frame plus boxed it in by connecting left to right side, got new hangers and welded those up and then reinstalled the shackles, leafs and axles. (Tandem axles) Works great! Oh, we had to extend the brake wires due to the extra lift.

It helps that my buddy is a machinist and we had all the equipment to lift and block the 5er as we did the work. I learned a lot!!

Sure, lots of members have done that. There is an excellent post here that was recently done and explains, with pictures, how he lifted his rig. Many others have done basically the same thing or had dealer do it.
Barney