I lifted mine with the 912's and adjusted the torsion bars but didn't flip the ball joints. It aligned just fine so I am not sure you have to do it... preference? I wanted to flip them but the bolts would not come off so we would of had to cut the bj's off and I didn't have any new ones so I left them as is. The rear springs... you just have to jack the VX up really high to get them out (that's what we did anyway) - the 912's are the same length as the OEM springs so it's easy enough to put the new ones in. So really, all you need is the tool to turn the torsion bar bolts and a good jack I guess.
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