V8 water pumps - plastic or steel?

I have just been asked this question but the parts lists don't list the differences just different part numbers so there is a difference but what is it?
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I've just learned from Don with the e39 group that between and including '97 - '99 the water pumps on the 6's had metal impellers. After that they were/are "improved" plastic.
Does anyone know if these metal impeller water pumps are also on the v-8's?
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Sir Hugh of Bognor
The difference between men and boys is the price of their toys. Intelligence is not knowing the answer but knowing where and how to find it!
Hugh Gundersen snipped-for-privacy@h-gee.co.uk Bognor Regis, W.Sussex, England, UK
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"Early" V8s are plastic, later ones are metal.

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Email: snipped-for-privacy@unixnerd.demon.co.uk, John G.Burns B.Eng, Bonny Scotland
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If I had a choice, I'd get the metal type.
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About 2 years ago the water pump on my 98 740iL went bad. I don't know if it was the original or not, but what was in there was metal. I replaced it with another metal one from www.bavauto.com . However, it only lasted about 1.5 years. Needing it right away, I went to the BMW dealer near me and was given a plastic one. Apparently that's how they make the new ones.
Kyle. 98 740iL 01 525i
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