1 - if the driveshafts are rubbing on the arb them notching will do nothing. You need a new arb that goes under the drive shaft or cut it off.
You only need a notch when you have a good arb that goes under the drive and your low enough to make the driveshaft hit the chassis.
2 - if all four wheels are making weird noises then I assume you need spacers to clear the struts etc to stop them rubbing.
Hope this helps
