I will write of the Datsun 1200 here.

In Australia, two models only. The cheapest was the "Standard" & it was built down to a price.
Next up was the DeLuxe. More features, more nice, more cost

In Japan there were two more models above the DeLuxe. Next was the GL [Grande Luxe] This had even more features & it naturally cost more.

The top end model was the GX. This was the go-fast version that was based on the GL. It was basically a GL with more black parts inside & out. It came with a special 1200 engine that had larger oval shaped ports, double valve springs, sports camshaft & twin variable venturi Hitachi carbs. [like SU carbs.]
There was a 5 speed gearbox available as an option from sometime in 1972 in the GX model only & the car was commonly known as the GX5.