Current setup:
1998 Audi A4 1.8T Quattro, dark blue, Carbonio CAI, APR Inlet Tube (Turbo+Intake), TAP 50 HP Chip 2, 12.5 psi, Straight Pipe, Milltek CB Exh, 17" OZ F1 225/45-17, Power Slot Rotors, Hawk Pads, SB Stage III clutch

The OEM KO3 will be replaced next week with a custom built K04 (tighter tolerance, better flow, etc.).

What should I do to accommodate the new turbo?
- should or can the TAP stage 2 ship be modified? How? And who can do it?
- I read about the diverter valve being or becoming a problem?
- Are the injectors holding up?
- What boost would you run and how/where is that changed?

Any suggestions as to what MUST be done and what SHOULD be done (in both cases for safety/longevity and performance reasons).