torsion bar size

Are the bars from the 4x4 any larger diameter than the 2wd bars ?? and can they be swapped in to a 2wd truck ??

why are you wanting to put 4x4 tor. in? did one break or what?

I'm lifting this one and the larger bars would allow me to crank it up more. just like aftermarket bars give a better ride when cranked down.