I just got these assembled over the last 3 evenings and was pushed to make the first shipment to TRC, so I haven't done a complete aftermarket install yet. I have placed 6 cells in with an "L" shaped arrangement saddle pack. I intend to use an old Shredder receiver and either a Flash or Spy, less the case. The ESC will be arranged down the centerline. The receiver will fit between the motor and the servo. These components have been dry fit and they will work. The other option is to shrink wrap the Spy and place on 1 side of the centerline and shrink wrap an XXL and place on the other side, possibly pyramiding them towards the center of the roof. Either way, with the main weight of the batteries laid flat, it should help to keep the CG down.

Ultimately I will use Atomic Mods Li-Ion cells, on order just waiting for the new shipment.

The front Diff gear is fully protected. The cut out is still needed but with the chassis thickness, there is no lower projection of the gear below the chassis. The cut out could indeed be covered with a piece of tape without interference.

Thanks