Last weekend I mounted an electric fan on my 66 just as a safety thing for cruises and parades. I'm also running the 4 blade non clutch fan.
My question is, I mounted the electric fan in front of the radiator and ran a wire to the dash with a toggle switch. Is there a down fall running the fan in front of the radiator? The more I think about it I think it could of been a bad idea with dirt pushing into the engine compartment, air restriction.
I will be starting the car for the first time this weekend. Am I just being paranoid? or is this going to cause problems?

It doesnt really matter but its a 66 496.

The turbulence between both fans will cause issues with the incomming air and wont do any good to improve cooling. Pusher fans dont work as well as pullers in the first place.

Any good fan that pulls air in from inside the radiator will work just fine. Electric or engine driven, there are good chioces in either option that work great without any extra help.

Pullers work better. But if you want to increase airflow at idle, which the four blade stocker didn't do well, you should be okay. At higher speeds, the air flows of the two fans could compete, but you could leave the electric off as you will have ram air effect. If you are not getting good cooling at higher vehicle speeds, then your electric pusher is a crutch for a different problem and you should look elsewhere.