I just bought a timing belt kit for my r33 and he sent me the water pump for the r34 neo which part number is 21010-AA527 but the actual one for the r33 are 21010-21U26.
I have sent a message asking him why he sent this one and he repled
"Hi there,
They are interchangable to all RB25DET, MOST RB25 guys prefer that one because there had been a few issues where people had coolant leaking around the slotted hole on the 21U26 pump, that one does not have a slotted hole so the sealing surfaces are much more substantial."
Is this true or not?