I use a dual fan setup out of a 95 ford windstar. It fits the radiator perfectly and the install is pretty easy.
Downside is they are less reliable than a conventional fan, as in they can fail without you knowing it, however with a dual setup with each fan on it's own relay it's not all that likely for them to both go at the same time.
Chev-hell sells used ones that he gets a deal on. If you are interested contact him. We both have the same fan setup and I think it's pretty hard to beat.
Another option is the lincoln markVII or something, it's a single fan setup that also works well. Others on this site use that fan and i'm sure will chime in with some info for you.
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Chris Dagenais
'71 Malibu with a home built 454!
[email protected]
"Our balls are bigger

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CDE Power!