91_2600i
+1y
Welcome to the forum!
In the states, the B2600 was made in 87 & 88 with a carbureted "Mits" engine. Starting in 89, they had a Mazda engine (G6) that was fuel injected. I have read that Mazda bought the engine tooling and/or rights from Mitsubishi for it, but I don't know if that is true. The trucks were only built here through 93. I would be real surprised if that truck has a Mits engine because the Mits was never fuel injected in these Mazda trucks in the states. The "Bubble Hood" would also be telltale sign of the Mazda G6 injected engine in the states.
If you look at most all of the components for the G6 engine (Mass AirFlow, Distributor Cap, ECM, Solenoids, & many others) most of them were made by Mitsubishi. So I think the owner has seen Mitsubishi plastered all over those components and assumed it was a Mitsubishi engine. But it is considered a Mazda engine.
They are very durable and reliable but have two Achilles tendons. The ECMs and fragile heads if overheated. If you don't overheat it and keep an eye on the ECM, it would probably make a reliable truck. Many owners get a bad ECM but miss-diagnose it and end up replacing other components before finally figuring out it's the ECM.
If you double check the engines (probably both years use G6) and then check the transmissions (92 vs 96.... almost certain they would be the same too) then in all likelihood, they are the same and will swap. But do your homework - things could be different down under!
I bet a fellow Aussie will be along to to confirm (or deny!)