We cut out our metal "frame correction" pieces. We tacked them loosely in place. Realizing it should work perfectly, we knocked them off and moved onto leveling the chassis before we began any permanent welding.
We had a table laying around that we decided to bolt to the ground and level the top of it. We then removed the rear end out from the chassis and picked up the main body. I clamped a 4x2 we had laying around the shop underneath the frame rails as we welded our single-piece "hockey sticks" inside the frame.
It will take me some time to get all of the drilled holes (you will see what I am talking about; we added them so that we could weld in our inner braces).
Here are the pieces tacked in place (roughly):
Since we are removing the gussets that were welded on the outside, we are moving some strength to the inside in the form of these solid "hockey stick" braces we made:
Mocked up:
Another shot:
Front crossmember going in place:
