There are a couple of other considerations on the Boxster engine in a
Vanagon idea.

The Boxster is a mid-engine configuration (i.e. engine in FRONT of the
transmission). The Carrera  is rear engined, just like our Vanagons.
If you happen to choose to use the boxster transmission instead of a
Vanagon transmission, then you'll have to work on the
innards...otherwise you'll have 6 reverse gears and one forward one.

The Boxster is either a 217 hp 2.7liter 6 or a 250hp 3.2 liter 6
cylinder engine. The subaru SVX is a 3.3 liter 220 hp 6. Of course it
has been put in to many Vanagons, so maybe isn't much of a challenge.

Yes, I know you already have the engine. After watching "Rides" on
Discovery HD, I know good shops can do just about anything...with
unlimited funds. If these guys are good and in the DC area and are
willing to work on Vanagons, I sure want to know who they are. :)