A front axle adaptor kit, having a front differential assembly, first and second shock absorber brackets, a spring support bracket, a track-bar bracket, and a dampener bracket to convert a two-wheel drive production truck to four-wheel drive enabling a drivetrain that allows all four wheels of the truck to receive torque from an engine of the truck. The truck has a transmission system and is retrofitted with a transmission to transfer case adaptor kit, and a transfer case parking brake system adaptor kit and support mount.