How much CFM?

[78 Chevyrado]

I'm looking at buying a set of electric fans for the truck.  t's a 78 c20 with a 350sb and th400 trans, and A/C.  I do have a tranny cooler in front of the radiator.   I'm wondering if anybody knows what the stock belt driven clutch fan does CFM-wise, so I can figure what setup I want.  for example If my stock fan pulls 3500cfm or so, then I don't need a 9,000cfm fan, since the truck has never overheated.

Thanks guys!

[VileZambonie]

Because the stock fan uses a clutch and a shroud it varies. Go with something that can move 5,000 cfm if you live in a warm climate

[SUX2BU99]

5000, wow, that's a ton of air. Although he lives in Georgia so I could see why that might be required. Do they make fans that move that much though? Most any I've seen in the mags move up to 3000 but that's about it. Although some OEM elec dual fans can move a lot of air like ones for a Lincoln Mark 8, Corvette, Viper, anything V8 powered with a/c really.

[78 Chevyrado]

Thanks guys!  I'm off to see what If I can find a setup I want to pay for