Essential i.m.h.o. to know before you start tuning the car.
This is where the original pump is situated ...
... and this is how the original pump looks like ...
Sadly though there are at least two different variants of the original pumps available, with a short and long lever arm.
If fitted with a long lever arm there should be a spacer between pump and engine block.
The pump in the pictures above is off the later variety with the long lever arm + spacer