I had the same problem whit the full piper 285 cam kit on my Mk3 Cab.
whit properly set-up vernier pulley and without it wouldn't pass 5500RPM

This morning i decided to install my original Cam.
now it makes 7000RPM and more (no limiter)

Does anyone have any idea what the problem is here ?

Greets, Thro
(belgium)