What transmission are you runnnig? RPM's are more important then anything else in the Vanagon...
If your serious about reliable power get Giles (see vendors section) to do the injection pump mods, $1000 range and your done. I would not get to wild with DIY stuff unless your willing to invest a few hundred in temp guages like EGT, oil temp etc. You can fry an engine in a Vanagon much faster then a car due to the weight/resistance. Intercooling is important in those beasts also and consider an external oil to air cooler (not just the oil to water cooler). You could raise boost levels, intercool it, add fueling and swap boost pin, get rid of EGR system, you will see decent power.
I have an 82 Vanagon diesel still 1.6 non turbo sitting inside now for 6 years waiting to find time...
Greg