I used to be the engineer at FoMoCo on the Effies that were sold in Aus.

The 4.2's are very tough (as is the rest of the drivetrain). They suffer (badly) from turbo lag under 1600rpms, and aren't hugely strong above that either, but if you aren't running a race you probably don't care... that said the comparable Patrol/Landcruisers of similar vintage were hardly rocketships. They only came with the manual trans (which is good - as the 7.3's only came with the auto in the crew cab... and they can have a habit of going bang).
Early 4.2's only had lightweight springs underneath them at the front, so they can sag. Check the spring codes, and look to see if the vehicle is sitting straight (they start to sag more on the drivers side).

As for fuel, they don't use much less than a 7.3, probably around 14l/100k on the highway depending on driving style/what you are towing. They are "tractor" engines... i.e. completely mechanical, unlike the 7.3 which has electronic controlled injection, which means its much more likely that your local diesel mechanic will be able to work on it.


The size of the fuel tank is 113l for crewcabs (all Aus delivered crew cabs came with the 6.75' "short-bed") if I remember correctly. The fuel tank for super and single cabs is ~147l (both only came to Aus as long beds). The duallies delivered here had 150l tanks (narrow-chassis)

The only issue I foresee with the 4.2 is getting parts for the engine. The 7.3's are pretty much exactly the same as what was in the states, so getting parts for them is easy, but the only other markets where the 4.2 was sold was South Africa and Argentina/Brazil (where they have been sold with them since the 80's)