I did the swap on an T-Rex 600 electric, which is now in the Align 500E fuselage. I did have to relocate the tail rotor servo as it will contact the fuselage in its standard mounting position. It only needs to move forward just a bit, but does need to be moved.

My nitro 600's have the tail rotor servo mounted forward, so and would not need to be relocated, however the LE version may have the TR servo in the same location as the electric, and thus need to be moved.