Is your Kombi misfiring or not running right? Could be as simple as a poor spark. It might be time to replace your spark plugs. These are a very cheap item and will make a big difference to the running of your bus.
These are equivalent plugs to bosch W7CC and will suit VW Kombis with type 4 engines (1700, 1800 and 2 litre). Generally speaking this is most baywindow Kombis from 1973-1979.
The gap should be pre-set, but check that it's 0.6mm.
These are not suitable for Kombis with type 1 upright engines.
This listing is for a set of 4 plugs.