Ray hit alot of points... There will be 2 "pockets" for lightening, one in front by the servo, which also acts as clearance for the servo saver if you mount the servo flat (I would recomend it) and another pocket under the t-plate... There is no other room to put any more pockets in the chassis. At some points it's a half inch narrower then the L4.
One other big point in which I liked, the body mount position is wider, longer, and adjustable in the rear. I had more downforce and my light weight body lasted longer!! (more support)
-Wayne