Yes, there are three servos in the tail. There is a small access panel just in front of the tail wheel. The rudder servo sits facing towards the bottom of the plane with a long arm sticking out bth sides of the fuseladge. The rudder is a pull pull setup with short wire pushrods instead of cable.

Wait till you see what a pain it is to mount the wing retainer springs through that small factory access panel. I enlarged mine and the front of the panel is held in place with a sheet of light ply overlapping the front edge. I only need four screws to hold the access panel in place instead of six and the panel is larger which makes it much easier to get at the wing mounting springs ect. Making the bottom access hatch is much simpler than making a top hatch and you have no hatch lines on top of the aircraft.

As far as balance, I had to cut the factory motor box off the firewall to fit my RCS 180 (it was too long to fit in the cowl when mouned on the end of the box). If you do have to cut the motor box off to fit the RCS 140, realize that in doing so you are moving the weight closer to the CG which will make the plane balance tail heavy. If it does you might have to mount the rudder servo under the cockpit area on a pull pull to balance without lead. With the motor box cut off and the ignition and battery mounted to the fire wall I was able to balance mine perfectly with all three servos in the tail with no leadweight.