I have owned and worked on both Cruiser & Patrol. I have been around every model of each from the 1950s to about 2005.
The Patrols are all around more stout. Diffs are much stronger, trannies are super bomber, frames are more stout and only one engine in 50yrs was a pos. That was the 3L TD and it was only a problem in the first few years of production. After that it seems Nissan fixed the 3L that is well known as a hand grenade.
A big part of the reason Cruisers got much more aftermarket support is simply due to them being sold in the USA. Countries like Australia have many regs on what you can and can not do to a 4wd. And I have asked my Patrol friends in Aus, why are there no axle upgrades for Patrols? They say....stock it is strong as all hell so no need to upgrade! There is a reason that Patrol diffs happen to be the most popular diff swapped into a truck down under. Most of your comp trucks down there run Patrol diffs be it a Toyota, Suzuki or whatever.
I am not trying to say one is better then the other. They are very similar trucks in nearly every aspect. Stock though, the Patrol is more stout and the Cruiser is more plush. If the Patrol continued to be sold here after 1969, well things would be much much different today in terms of how the truck is supported by aftermarket companies not to mention the publics perception of the company Nissan and the vehicle that is the Patrol.
Oh and Colombia has the longest histroy with Patrols in this part of the world, ie the Americas. The first ones started being sold in Colombia in the mid-1950s and are still sold today. They got more models then just about any other country in the world. The only thing Colombia lacks a lot of in terms of Patrols is diesels. The only other country in the world I know of that got so many Patrols would be Saudi Arabia.
Lastly, FYI the Indian Army adaopted the old 60 series Patrol as its military
"jeep" and they built them in India from the late 1960s until the 1990s. In India the Patrol is called the Nissan Jonga.
