The caster on 240s can be made adjustable by sloting the mounting holes on the lower A arm rear bushing mount. Use a round file to slot the three holes in each mount horizontally. Moving this mount side-to-side will then move the spindle forward and back thus changing the strut angle and the caster. The three adjustments,camber,caster,toe will still be interactive. I strongely suggest an alignment shop that has computer print outs of before and after specs and getting the service option that references the rear wheels.