So exactly what boost is it making, when does it surge, how much boost when it surges etc etc ?

And why vernier pulleys on std cams ? Are you sure cam timing is correct ?

What ecu are you using ? Cant it control boost ?

Bigger turbine housing may help...or so might a more restrictive intake before the turbo.
Although even a ported front cover doesnt mean there is no chance of surge, although it should help.

Shouldnt cost that much for a ported cover ?