Like everyone said, the rear is easy.

I like to narrow the front ends for use on a CJ. Go to the Jeep-tech section off-road.com and look for the Dana 44 conversion articles. I have an article on narrowing a FSJ front end to use in a CJ and so does my friend Jefe. I think it's actually easier to narrow the housing than to outboard the springs. Narrowing also makes the front axle exactly match the width of the rear, normally front axles are about 3" wider.