To convert the CK3568A kit from Mk.5 to Mk.6
A recurring problem with Saracen in hot climates was exhaust fumes being sucked inside the crew compartment through the superstructure vents. This was cured by the adoption of Reverse Flow Cooling. 
The rear pair of engine lids were replaced by ‘beehives’ – louvred boxes built into the lids that acted as air inlets. Air drawn in was blown through the radiator where deflectors ducted it downwards and outwards. However, when the vehicle was stationary, hot air coming out of the front would blow over anyone standing close. A large sheet-metal deflector cowling was fitted over the radator grille with a rub­ber deflector to direct hot to the sides. With this fitted, Saracen Mk.5 became Mk.6. The distinctive vertical outlet pipes at the rear of the hull were also deleted.