We spoke to engine rebuilders with knowledge of the ADE236 motor, and their advice is NOT to turbocharge this motor or it will not last. It was originally designed by Perkins to be a naturally aspirated engine with lots of torque, so it is best suited to low-speed applications. If you need speed, buy a different vehicle.
For detailed technical advice on the ADE engines, try Colman’s Engines in Johannesburg (011 334 7673) or SP Motor Engineers (SPME) in Paarl (021 862 5400).