Yep the 410/413 aka Narrow track Spring spacing is loads better, less roll stiffness and more tyre clearance once samurai axles are fitted.
I wouldn't be too worried about making it wider though....your ass will be puckering well before it tips over as it is
Personally I would loose the shackles and go back to standard length ones, longer shackles do more harm than good to the off-road ability with standard length springs.