I'm not an engineer, but I really don't think that just slapping a coilover in place of the stock shock and asking those two little pieces of bent sheet metal to handle several times more force than they were ever designed for is a good idea.
Think about how much metal the torsion bars are supported by in the stock setup. They have their own ceossmember on one end and the other end goes into the meatiest part of the lower control arm.
If you were going to do this I think the right thing to do would be to seriously reinforce the mounting location on the LCA's, if not fabricate new, much heavier duty LCA's, and at minimum run a brace over the engine from one upper shock mount to the other, if not build entirely new (and also braced) hoops.
What would be the end goal? Better street handling? Better over whoops and jumps? I see that he did it for street/track reasons but he's also driving a lowered 4x4, which is kind of a niche thing to begin with.
I think the only real benefit would be adjustability, but you can still do that with high end regular shocks too.
