to clear up some confusion in this thread, the starion/conquest(starquest) are all 2.6 astron motors. all 2.0 g63b, 4g63, and 4g64 are sirius motors and the parts are not interchangeable. any 16 valve head swap will require more than the head to make it run, including the computer, injectors, coil pack, and intake with throttle body, and a custom exhaust manifold. You will also need to change the fuel pump to match the needs of the new motor.