Across Australia in a 1948 Buick
The straight eight was yanked out and replaced with a six cylinder Perkins diesel, recovered from a burnt out Ford Thames truck. The team figured they were more likely to encounter dieselene at the various settlements and stations in central Australia. Most of the properties ran diesel powered generators to create electricity, hence it was far easier to obtain than petrol. The other advantage is the diesel motors are not so fussy about octane ratings and can be coerced into accepting all sorts of mixtures as fuel (you need to buy the book to discover more of that story).
The motor was too heavy for the American front suspension, so extra coils were added to give the car ride height and strength. Extra cooling was supplied by adding a large copper tank to the radiator, which could also serve as emergency drinking water.
To give the right gear ratios for the slower turning diesel, a Packard overdrive gearbox was sourced that gave extra speed. All this meant a lot of modification to gearbox bell housings, clutch, torque tube and propellor shaft. This amazing work was all undertaken by Keith with rudimentary engineering and mechanical facilities.
The Buick towed a trailer and dinghy (also hand-built by Keith) over good road and bad, mud and river crossings.