 After working with Callaway on the four pin front diff Land Rover decided to put them in all of the 1999 Range Rovers since the 4 wheel traction control that added ABS regulated traction control to the front axle in 1999 also put extra stress on the front diff (Range Rovers from 1993 to 1998 only had traction control on the rear axle).<>

The Callaway dual exhaust had reduced backpressure and was similar to the dual exhaust that all NAS Range Rovers got in the 2000 model year.Changes to the exhaust system were made rearward of the catalyst "Y" pipe.