6x4 (1978–83)

The 6x4 shared the 4x4's cab, engines, automatic gearboxes and permanent four-wheel drive to the front two axles; the third axle is a trailing unpowered ('lazy') axle. Allisons gives a 3,525 mm wheelbase, a length of 5,445 mm and a payload of 2,900 kg, against 2,800 mm, 4,940 mm and 1,500 kg for the 4x4. A fully automatic 6x4 of 3 tonnes payload was on the Stonefield stand at the NEC Motor Show in October 1978.

The type's best-known users were airfield fire services in the Highlands and Islands: a Carmichael-bodied P5000 6x4 crash tender served at Barra, where aircraft land on the beach. In 1993 the Samuelson film and television fleet at Pinewood still ran a Stonefield six-wheeler for rough-terrain location work, the only vehicle of its fleet to get through snow to a Poirot location in the Derbyshire Dales.