CURRENTLY OUT OF ANUAL OWNED BY A&P AND IA 1) blue print the engine, ie balance all moving parts inside, crank shaft, cam, etc 2) flow balance the cylinders so they are equat in volume and the ports flow the same volume 3) Lycon has an STC for instal of an "O" ring between case halfs that prevents oil leakage and I had that installed 4) rework intake seats in the pan for correct fitting "O" ri......more.