It's not saying you cannot use them. (yet) It's saying the Truck must be designed to be 'capable' of supporting a full size pack. So those Midmotor 22's and a few others that 'must' use short packs when in that conversion, are in limbo right now if they are 'legal'. Next they'll have minimum size specs for a battery. Just be aware before you go out and buy this stuff! (depending on your track, goals, and how much said track gives a shit about ROAR.