I do about 1,000 alignments a year, and been doing them many years. If you drop the front end, you WILL change camber, caster, and toe. The front end travel will change everything. If you just change the rear height, caster will change the most, but, you are still transfering weight to or from the front end, and that will change camber and toe some. If you raise or drop your front end half an inch without aligning it, I'll bet you don't get 10,000 miles out of your 50,000 mile tires. That's just my estimate, I've never put any mileage on one after altering the height.