The back definitely should not drop. Weight transfer--yes. Front lift--yes. If the back drops, it's because the differential is lifting, thus lifting the tires off the ground. That's the last thing you want for traction. Look closely at real race cars with stock type rear suspensions. The rear of the car lifts too. SS springs of the correct weight for your car and a properly adjusted pinion snubber are the easy way to do it. Cal-tracs are another way to prevent the front from wrapping up and the right from lifting.
