ONE thing that hasn't changed with the BA Falcon is its employment of the obligatory large Aussie sedan layout. Like Commodore, Falcon remains a rear-wheel drive four-door with a longitudinally mounted six-cylinder engine residing up front. In Falcon's case it's a cast iron/alloy head inline six measuring 4.0 litres and using twin overhead camshafts and four valves per cylinder - versus Commodore's cast iron, two-valve pushrod V6. All BA Falcon sedans now employ a two-piece driveshaft.