whats that for???

When you lower an EXT cab truck, the driveline, which is 2-pieces, makes an angle in to the carrier bearing. Raising the CB corrects the angle. Driving with the CB at an angle will cause unnecessary wear and tear on it.

I have a carrier bearing shim kit, and i still have alot of vibration especially right out of first gear. Also it makes a weird noise when i hit about 50 around the drive shaft area.

hows that workin out for you? im lookin at gettin a drop, but am kinda hesitant on that carrier

It's good. Before installation, I had bad vibrations in 3rd and 4th gear when accellerating, and when coasting on the freeway. Now, and with pinion shims for the rear axle, the vibrations are gone.

whered you get the pinion shim for the back