Adding a pusher fan.

No actually you're missing my point. What I'm saying is that you can only push or pull as much air with the fan(s) as the stronger of the 2 will move. The weaker of the 2 fans with actually just disturb the air flow created by the other fan and therefore actually reduce the total flow. You're better off just running one fan. So it's like this if on one side of the radiator you have a fan that can move 500 CFM of air and on the other side you have a fan that moves 300 CFM, you're not going to be getting 800 CFM of air flow. You probably won't even get the 500 because the weaker fan can't keep up and just gets in the way.

And you are missing my point. Doesn't matter if one is taking away from the other. IF the factory fan is inefficient to cool a motor down while at an idle in traffic or not. IF the factory fan is not adequate enough, then there is a problem. In my opinion it would not be to my advantage to remove that fan and run any kind of electric fan by itself because by itself, pusher or puller and take a chance on it getting a short, blowing a fuse or just not working and then run hot. In my opinion it is stupid to run an electric fan all by itself UNLESS you are doing it at a track where you are only running a 1/4 mile at best where you can control the situation. At least you would have some kind of air circulation. Like I said earlier, I have this setup on my rat rod that is running a 454 BB engine at it runs fine. MAYBE one is taking away from the other some, I don't care. It is getting the job done. Maybe if I ran a shroud on it or on the Duster, I wouldn't need a pusher, I don't know. But if I get in traffic and sit for any length of time and the temp rises to 195*, the pusher comes on and it comes back down to 180*. That is all the info I need. And to the OP, I would say do it. That is why I chimed in on this. Not to argue the point with an aerospace engineer or anyone else. I just stated the fact to the OP that this does work and I intend on doing it to my Duster like I have done on the rat rod.