Here is what I did

I put the battery above the fuel tank. moved the engine out 1/4 inch from what the book calls for, added 3 OZ of weight under the fuel tank and I balance right at 4 1/2 inch. You could replace the 3OZ with a heavy hub/spinner but I feel that adding that mass to the engine will increase the time it takes for the prop to spin up and I want the quickest engine response I can get to pull myself out of the stupid things I may do.

I use an OS .46AX with an APC 11x5 prop for now. Eventually I will change the prop to the APC 12.25X3.75

I started out with the book low rates set for high rates and then cut them to 75% on the low rates and on the next flight after trimming I went with the book throws on both low and high rates. This was after flying my LT-40 Kadet for around 30 flights and a SIG 4 Star 40 for about 6 flights.

I find this plane a blast to fly and lands just as well as my LT-40 did with the CG at 4 1/2 inches. The 11X5 prop with help slow the plane until she gets used to it. It took no aileron trim and just 4 clicks of down elevator with 1/2 throttle. I can lift the thing off the ground in about 10 feet if I want but I have no right thrust built in so I need to give it rudder and aileron to keep it from rolling left or tip stalling.

A heavier engine would elminate the need for lead though. The recommended engine (EVO 46NT) is lighter that the OS46AX which would account for some o the weight difference between what you need and what I need.