Cylinder heads are where the power is made. A 3 angle valve job will help your heads flow much more air and create much more power.
Larger pistons and cylinders is a great way to add more power to your VW motor.
With higher lift cams and larger valves, you need more seat pressure. That means dual springs!
There is no better way to clean your cylinder heads than to run them through the bead blaster.
A good quality rebuilt factory head will out perform and out last a Chinese built head - Every Time!