[perelet]

Pump itself does not need to be strictly part from 996/997 cup. There are MB, Toyota etc pums that are as good. As far as I understand pump should be from 2005 or earlier car, later cars have CAN bus connector, also some pumps from later cars have variable assist pressure.

Pre CAN bus pumps fall in to 2 cathegories -

1. constant load pump - works all the time at full load.
2. variable load, pump pretty much idles when steering is straight, when steering is turned pump has senses it via liquid pressure switch and ads rpm's.

Type 2 pumps do not create alternator/battery load while steering is straight.

There are good threads in 928 land about conversions.

Oleg