So are you going to shorten the sidestand or just bend it out some to make up for the drop? You can't just shorten the stand the same amount as the drop and expect to keep the same lean angle. It might be close but you need to do a little math or just use trial and error.
So using my little MS paint drawing.. (at work so I can't use photoshop
)
(click to enlarge)
Let's just say the bike leans over at a 20 degree angle from center (70 degrees from the ground). If you lower the bike 2" (remove two inches from the tire contact patch to the sidestand pivot) then the side stand pivot point will only drop 1.88 inches due to the 20 degree angle.
Since the sidestand is at a different angle than the lean of the bike, lets say 45 degrees, you'd need to take off 2.66 inches to have keep the same lean angle of the bike.
The problem with that is the distance from the sidestand contact patch and the tire contact patch (along the ground) just got 2.56 inches closer. That means a less stable bike when it's sitting on the sidestand. That's why it might be a better idea to bend (change the angle of) the sidestand to keep the bike at the same lean angle and still keep the wide sidestand to tire contact patch distance. How much you need to change the angle of the sidestand (bend it out) depends on the length of the side stand. But you can't use the actual length of the sidestand, because the pivot as shown in the picture above is imaginary since no sidestand that I've ever seen mounts to the centerline of the bike. Imagine in the image below that the green line is distance between the lower rails on the bike and the stand is mounted to the left rail (aren't they all?).
(click to enlarge)
So you'll need to take than into consideration when calculating everything. There are also a few other things that could be taken into consideration such as how the suspension was changed to achieve the drop and how that affects the static sag, etc., but I'm not smart enough to figure all that out and it might not matter that much anyway.
So instead of doing all that math, after you drop the bike, I'd just heat up the sidestand with a torch and keep bending it out until you get the lean angle you want. Then again, maybe removing an inch or two from the distance between the sidestand and the tire contact patch wouldn't be that big of a deal so shortening the stand might work just fine
and to new ones too. I know a little...mostly from more experienced members holding my hand but I have learned. I still have lots of stupid questions to ask so don't go anywhere ok? geez! 
with 650skull.
