if you are looking at lowering the back about 2" the easy way is to use boogeys rear lowering bracket. I am just about to order myself some. there are a bunch of people on this site who have done business with him (he is a member) and all have been happy as far as I know.
http://marketworks.com/storefrontprofiles/deluxeSFshop.aspx?sfid=73147&c=49245
