No noticeable effect on turning radius. Actually, since the tires no longer rub on the frame/suspension on the FSJ, I can turn tighter than before - its like I swapped on some wider axles or deeeper wheels, but I was able to keep my stock wheels. It also made the front hubs not stick out so far, looking like something waiting to get smashed on a rock.
Also no noticeable effect on tracking/alignment while at cruising speed. There will be no changes to any handling aspect if the spacers are just added to the rear to even out the track, like the case of our Eagles, which need some spacers to look correct, to me.
Btw, forgot to congratulate you, vangremlin, on making your already awesome car look even cooler.