4 speed 2.0 Aircooled box , but you also need gearlinkage end, front mount to fit it- you will need to combime the mounts or move the engine and change the driveshafts and use standard mounts.
AAP 2.1 box 5 speed - also needs 5 speed gear stick and rods set up - front to rear, front 5 speed petrol mount also needed
both the above will give you the best cruising speed that vw can offer.
from there up it just depends how deep your pockets are
depending on the specific engine - your type of van - how you drive - wheel / tyre combo / how its loaded - will all create a specific built box
aidan talbot is your man for the own spec box.
http://www.aidantalbot.com/live/" onclick="window.open(this.href);return false;