I have an 1100 mah NiCd four cell pack mounted under the cockpit with the RX mounted behind the tank. Used an OS aluminum mount for the 160 FX. with a Pitts style muffler. Three servos in the tail with a direct connection to an Ohio Superstar tail wheel. Used a DB 4" aluminum spinner with the adapter. 16 OZ Dubro tank mounted forward with a large Dubro fuel valve mounted in the cowling. Used a 1/4 scale pilot, slimline rubber wheels. Used 9 1/4 " from the TE and balanced on the numbers. I would think my tail-wheel connection would be heavier than the one you are probably using. Futaba 9001 servos on the ailerons and 9202 for the elevators and rudder. Futaba S-148 throttle servo mounted in the fuse per directions.

Pictures may help you better understand the set-up.