All that is needed to improve the engine is to use proven T1 performance
parts:

Solid rocker shafts
Roller tip aluminum high Ratio rocker arms
racing valve locks
Cromoly cut to fit push rods
Cromoly valve spring keepers
Counterweighted cranks
racing clutch bolts
lightened flywheel
slightly improved cam
mild head work
ceramic coatings of head sealing surfaces to stop corrosion problems
Full balance of all rotating parts.

Change to gearbox to a .457 five speed

Plus some other changes to create an engine -- gearbox combo that IF VW made
there would not be many complaining about a lack of power and not be swapping
out this engine for that nonsense... (MO)

MANY of the problems with the WBX are due to LACK of maintenance, using
incorrect coolant and not fixing a problem correctly/completely with the
correct part ... while there are some problems they can be easily fixed...

Robert