I was thinking, what if I took out the 3 inch lift spacers between the center portion of the IFS, you know, where the diff bolts to the engine? What if I take those spacers out and replace them with a solid steel bar or piece of square tube, weld it to the frame rails, bolt the center portion on to the bottom part of the tube and bolt the top part to the stock place for the engine. Might that make the center portion rigid enough to stand up to more abuse than the stock front end can? is this confusing to anyone else? here's a pic of what I mean, or at least where I think it would go.

 

saying this with out looking at my truck or the basics of the system i feel like the bottom bracket also attach to the lower control arm, giving it some sort of structure. with out it you would have a floating axle like sas or 4 link system with a axle like a noodle with two hinging points without a fixed distance, or structure. don't think your changing much with replacing the bottom bracket with square tubing or angle iron.
but i may have to see a different angle and look at my truck but thinking again whats the goal your trying to achieve with it.

 

scratch that i am completely lost don't know what your doing or if anything i said before would be even relevant