Although your tailshaft will probably be shorter than the Falcon alloy shaft, keep in mind Ford speed limit their models with these shafts to 180 km/h. They devlop bad harmoncs above this rotating speed and shake badly... leading to serious failures. The XR6 non speed limited models are equipped with steel shafts. You know Ford had issues with the alloy shafts, as the later E series models come with a pretty serious harmonic balancer by the yoke !