This is what happens when non-VW slang from forums around the world becomes 'accepted' - it only causes confusion.
'Type 4' refers to the big-block air-cooled 1.7 and 1.8-litre engines originally designed for the VW 411 and 412 sedans (not sold here). That's why they are called Type 4 engines - they were for the Type 4 range of sedans and wagons. The 1.8 was also used in the VW-Porsche 914, and was later bored and stroked to 2.0. The 411-412 never used the 2.0-litre version.
Detuned low compression versions of the 1.7, 1.8 and 2.0 were used in the T2 Transporter. In Australia you had a choice of 1600 Type 1 or 1700 Type 4 engnes in 1973, then 1600 or 1800 in 1974-75. In 1976 the 1600 was dropped and the 2000cc engine was the only option until the T2 Kombi was discontinued in 1979.
The T3 Transporter also initally used the 2000cc Type 4 engine from its release here in 1982, but it was an improved version with fuel injection, hydraulic tappets and different exhaust ports. This engine was discontinued in 1984 when it was replaced by the 1.9-litre Wasserboxer (Wbx) engine. This was not based on the Type 4, but on the Type 1 long block! This was later enlarged to 2.1 litres. In Europe they got more choice of different specs for these motors than we got here (eg they also got a 1600 Wasserboxer!)
VW model 'Types' come from the chassis number and after 1980, the VIN. Beetle chassis numbers start with a 1, for Type 1. Kombis start with a 2, for Type 2. The 411 starts with a - you've guessed it, 4. That's the vehicle model, not the engine. A Kombi with a Type 4 engine is still a VW Type 2, as the code refers to the whole vehicle. On the more modern VIN, the VW model code is the 7th and 8th digit of the VIN. So a T3 Kombi is a model type 25, while a T3 pickup is a model type 24. A T4 Transporter is a model type 70 (so it's no longer a 'Type 2'). A T5 Transporter is a model type 7H. But the Crafter is a 2E and the Amarok is a 2H, so technically they are still VW 'Type 2s'.
'Type 5' has nothing to do with Kombis of any generation. The only Type 5 VWs have been the Scirocco (model type 53); Corrado (model type 50); the Golf/Jetta Mk6 (5K); the Golf Plus (5M); and the Tiguan (5N). The Brazilian-made Fox is a 5Z.
For a good rebuilt or exchange Type 4 long block, standard or modified, contact Garry Williams at VW Classic Kirrawee.
http://www.veedubclassic.com.au/