[Spridgets] 948 Water Pump Questions

[Norm 2Bs]

I just bought a new water pump for the modified 948 Spridget engine in my
Turner racecar.  It's an alloy body with stamped metal impeller by GMB,
Japan.

The angle of the blades on the impeller are very nearly at right angles to
the shaft, whereas the blades on the cast iron impellers of the old pumps I
have are at nearly a 45-degree angle.  I find it hard to believe that this
new pump will do anything but cavitate at race-speeds (3,000 to 6,000 rpms).

Have any of you with race or street Spridgets had any experience with this
brand pump?  Is it good or bad?  I ask because I need to grind away
clearance at the top for the thermostat housing section of the head.  Can't
return it after modified.  Has anyone modified the impeller in any way
(blade angle, spot-weld, etc.)?

Thanks in advance for your help.

Norm Sippel
'59 Turner Mk.1
Florida, USA