The camber and toe will both change. The camber changes as the suspension moves through its travel range. The alignment specs are for tthe car sitting on level ground with the weight of the car on it. When you lower it, the suspension is in a different spot, so the camber will have changed. The toe also changes unless you have bumpsteer correction because the original suspension is known for having bumpsteer which means the toe changes during suspension travel. Toe will also change when you correct the camber. The only thing that won't really change is the caster angle.
it may sit higher than stock because of the fact your springs are old, and they do not measure the stock height. i know mine was about 3 inches shorter than stock before i got new 620 1" drops.
well, it had newish stock height 620's in it when it was aligned just recently. i also have a set of 1" lower 620's that i am considering throwing in. will it affect the alignment negatively enough to warrant not doing the swap or should i just rock it as is with the new springs? will camber be increased by putting the shorter springs in? it has the shelby drop on the uppers already if that makes a difference