Overheating pony

I have tried numerous things to keep my 302 cool. Milodyne water pump, re-curved duraspark, Three row copper, (used) griffin 2- row rad, and now have a brand new aluminum 2-1" core direct fit for the 64-66. With the electric fan from Hot Rod Air, it will only cool idling at night. During the day, in traffic will eventually overheat. With my previous two radiators, once hot, would never cool down even on a long highway run. Now, with the new aluminum rad, she cools going down the road, so the problem lies within the fan. The hot rod air fan supposedly pulls 2000-2500 cfm. I don't care what it costs at this point, I have wasted so much money experimenting. Is the solution a wider 67-69 radiator, or will a 3000 cfm electric do the trick? Will any taurus fans fit the 64-66?
 
We've run a 3 row copper with mechanical fan on a 302 without any problems unless coolant was low. We currently have an an electric fan on an aluminum radiator (~standard size) on our 347 no problems yet (not much mileage yet). any chance you've changed a head gasket lately and have them reversed?. that will cause overheating. I assume this is a recent problem and at some prior point you didn't have the problem.
 
Check the head gaskets. There's a good chance they're on backwards. Look at the lower front corners where the block extends out from under the head. If the gaskets are on correctly, there should be a corner of the gasket poking out as well, covering the corner of the block. If the gaskets are backwards, the coolant will shortcut back up to the heads and intake, letting the rear of the block and heads run hot.
 
What thermostat are you runing? Could be bad, could be rated too hot. Water not staying the radiator to long will not cool down causing you to overheat as well.
 
http://s125.photobucket.com/albums/p53/baddad457/ Click on the pic labeled "head gasket" This is a pic of the driver's side head at the lower front corner, you can see a portion of the gasket sticking out, just forward of the corner head bolt. There's another pic of a used small block Felpro head gasket, if you'll notice the corners, the closed end (front end) of the gasket has no notch cut in it, whereas the rearend of the gasket (open coolant port) has the notch.
 
Have you flushed the block out ? When I swaped the motors I removed the freeze plug and ran a hose through all the ports. So much garbage came out. That can clog your radiator and make it wothless for cooling.

Since you said you just put a new (used) radiator in, did you back flush it ?

An electric fan with a properly placed thermostat would provably do the trick.

Got a new radiator cap with a proper pressure rating ?

Do your hoses baloon when they get hot ?