Here is the process...
To put the Sullivan rods in the Extra, here is what you need to do.
1. Get some Sullivan blu/yellow rod.
2. Get a good servo, at least 100+ on the torque, with some speed.
3. Mount servo on hardwood rails in the middle of the fuse. (this assumes that you are using a servo on each elevator half and the throttle servo is mounted farther forward, preferably a mini servo.
4. run the outer portion of the rods just where you would put the grey outer rods on the GP kit (at the bottom closest to the bottom of the rudder.
5. One the epoxy and microballoons dries, cut the outer and sand flush.
6. Get a double horn for the rudder, several people make them, I think mine is a plastic sullivan product
7. fit it to the rudder, making sure that you beef up the rudder where it is going to go. I used 1/16" ply, shaved down the sides of the rudder and glued the ply flush with the rudder, then sanded.
8. when all done covering and stuff, mount the inner portions, golden clevises at the rudder end and 2-56 ball links for the other end.
9. Adjust and tighten, not too tight.
10. finish the plane and go fly.
Any Questions? email me. I have all sorts of tips on this bird. Mine weights a few ounces shy of the bottom weight limit. Good stuff!!!
James