Hey, I have an 85 Square body that has a 5/5 drop, and it sits perfect. As far as C Notches, you won't need them unless you go lower than 5/5, all you have to do is remove the factory bumpstops and your good. Look under the forums but everyone I have talked to/seen says they never hit either. Heres where I got mine from its all DJM so its good stuff.
http://app.infopia.com/Shop/Control/...44235232251238. Only thing you have to do other than putting the kit on is if your running ralleye wheels you have to shave like an 1/8" off the calipers where the wheels hit.
-Adam