Thats weird as i fitted 2wd coilovers to standard sierra hubs with no issues, you say your wheel hits the coilover, what wheels are you running which part of the coilover is the wheel touching? In my head ive got a picture that its the standard wheels and they are touching the adjustable spring platform?? If this is the case even if you change the hubs it will still do this, you will need to space the wheels a little