Complex sentence: The Ford Falcon GTHO Phase III was built for homologation, looked almost identical to the GT and was a modified version of the Falcon GT built in 1971 with a heavily upgraded engine, a four-speed top-loader gearbox and Detroit locker nine inch differential.
Split into simpler sentences: The Ford Falcon GTHO Phase III was built for homologation, it looks almost identical to the GT. The modified version the Falcon GT built in 1971 with a heavily upgraded engine, a four-speed top-loader gearbox and Detroit locker nine inch differential.