how to identify a 1.6 kjet?

I've been told by a few people my engine I've just put in my cabby is not a 1.8. It has an oil cooler and doesn't have 1.8 stamped on the block. I know all mk2 1.6s and 1.8s had that stamp but apparently not on the mk1. Can anyone give me the good news that its an early 1.6 GTI engine?

Also just to add to this, my top radiator hose exits the head just above the alternator, my mates 1.8 mk1 GTI has it coming out around the centre of the car, on the other side of the head.

As far as I know, all Mk1-based 1.8L engines have the coolant flange located between cylinders 3 and 4.

The 1.6L and 1.7L have the coolant flange located between cylinders 1 and 2.

As I thought, and upon more research it would appear I have bought a 1.6 Kjet, which I'm pretty chuffed about!