I think you may come into trouble trying to crack a genuine 400KW on a stock bottom end,the way I see it is to make that sort of power you will have to run pre mentioned parts at the least & then you will need to run fair sort of boost & ignition to get that sort of power.BUT to be able to run 18-20 Psi & some fair ignition curve you would have to run some sort of exotic fuel & still worry about breaking a ringland or bend/throw a rod.If any sort of reilability is to be had I can't see any other way but to Build A bttom end (dropping comp, good rods & pistons Ect.Hate to crush your hopes but been there before.Better to do it right once than do it twice.Cheers DJP.