I am facing a similar question... I am dropping an LT1 in a 75; since the LT1 has a cam driven water pump and no mechanical fan and I'm on a limited budget, I have limited choices. I grabbed a dual electric fan setup out of a newer caddy with a sideways northstar, I figure they should have enough flow for this motor and they were cheap at the pull-a-part. I nabbed the stock thermostat and wiring with them, I figure I will leave one on the thermostat and the other on a switch (it can also be wired to come on any time the a/c is on). I'm still a long way from having the engine in place (body is on blocks in the garage, frame in the living room) so I don't know how they will fit and work in the end, but I feel pretty good about it, and it's a heck of a lot cheaper than aftermarket kits. I have used electric fans out of a Ford Taurus in rock crawlers before with really good results. They work excellent in low rpm situations where a mechanical fan does little good, much more torturous than sunday traffic, and you can find them by the dozen in any junkyard.

 

I'm in the market for an electric fan as well, thanks for the great information! But which type of fan is better...a pusher or puller??

 

As long as you have the room, a puller is better. The fan will not only suck air through theradiator, but it will also blow air onthe engine to help cool it.

 

oh, ok great! Thanks! Is there anything you don't know Mr. 69??

 

Uhhhhhh...I don't know!

 

Well, while we're one the subject... How difficult would it be to wire an electric fan to a switch? That is, one out of a junker car, I'm gonna need electric for my TPI swap cuz my mechanical one is WAY to bulky and wont allow the MAF to fit. My bro says to steal one out of a Ford Taurus, but how hard it is to wire one of those things up to a switch and bypass everything?

 

Not hard. You can do it one of two ways. One way is togo with power to a switch and through it to the fan. Just make sure the switch is rated to handle the amperage draw of the fan.
The better way is with usinga relay. Your switch will have the same power going through it, but instead of going to the fan, it goes to arelay that you put under the hood near the fan. The relay will have "hot" power going into it, and your switch will activate the relay to make the current flow to the fan.
Why a relay is better is because you have good clean power going directly to the fan, with a short run of wire. Amperage naturally drops, and heat in the wire goes upas the wire run gets longer. So a short relay hookup to the fan gives it more power with less of a strain on your wiring.
If you dogo with the relay setup, you can also wire in an aftermarket thermostat controlled switch, with a heat probe that attaches to the radiator,which will tell the fan when toturn on.
And if youget a fan from a junker car, check the wire hookups on it. A lot of fans have more than one speed (single fan setups in a carwith A/C), so it could have more than one supply wirein addition to the ground wire.

 

Bob,
If you are using a late model Delphi (GM) or MEFI (Marine Electronic Fuel Injection) computer there would be a wire in the harness to operate the fans. The MEFI unit is used by a lot of aftermarket tuners for hot rods with no emissions.