FFS, it's clearly a PB motor, running on K-jet. The converter will probably have got longer fuel lines fitted, check the condition of these as they're very high pressure. Everything else motor-wise will be as per Golf2.
It's been fitted on diesel mountings and bellhousing, as it all just bolts up, although depending on the inlet manifold you may find the chassis rail's been beaten up to clearance it around the inlet manifold.
The pump isn't different, there's just a different pick-up fitted to it. IIRC the GTI oil pump is actually a higher capacity unit than the diesel ones, so let's hope whoever converted it used the original GTI pump with a different pick up.
Be very careful with the sump as it's alloy and they crack very easily.
You've got a better motor there than VW ever fitted to a European T25. If you have any questions, feel free to ask on
www.busgoons.com .
For big brake conversions to make it stop a lot better speak to Dave at
www.futbus.com I hope you enjoy the bus - they're solid motors, the GTI unit suits it well and it will give you a lot of pleasure.