Got my new setup running and all is good except I experience turbo surge at full throttle (pull) and part throttle (static load).

2wd cossie

Current setup:
- GT3071R.63 fullsize 60mm turbine wheel, 4" compressor housing (NO antisurge)
- 2wd Reyland modified external wastegate manifold
- Tial 44mm MVR ext WG
- 200block 0,5mm
- Stock camshafts
- Piper vernier pullyes
- 750cc Siemens injectors
- 4x4 modified inlet with 15mm spacer
- Slightly ported head by the valve seats by removing some material (about 10mm on the diameter taken off the curtain behind valve seat
- RS500 cooler, 3bar map, 3" pipe etc.
- MSD6A Digital ign amp.

What would you recommend me doing to this setup to avoid the surge?

1. Order a .82 turbine housing as the .63 seems too small, but Im not sure if itll solve the problem on its own?

2. I could machine the comp housing to antisurge spec?

3. Electronic boost controller? If so, which one?

Thanks!!