To save cutting the ball studs down there are 2 other things that you could try. Use AE shock "ball studs" You actually screw through them rather than being a ball stud. This has the disadvantage that the hole/thread in the wishbone will wear and they will end up loose. Also the AE spring seat allows the spring to sit about 2mm lower.
I used to cut the ball studs but was worried that if it was 100% accurate then i would be giving myself spring pressure issues.