Which front Vent to block?
 

I know most of the easiest aerodynamic modification would is to block the Front Raditor(under the hood) or the bottom vents (the bummer vent).

I choose to block the top vent because, I figure the the secondary smaller radiator block would be some sort of transmission cooler. I don't want my tranny fluid overheat. Second, there still is air flow passing thru the radiator to displace the engine heat from the bumper vents.

I see everybody seems who has to block the lower portion of the grille. I would like to see if anyone has any data regarding the temperature of the tranny fluid with this modification. I'm assuming the temperature would be slighter higher than normal.

Which ones do you block?

I believe the tranny fluid is cooled with the normal radiator and the smaller one should be something to do with a/c, at least that's the way it was on my car. I don't have any tranny temp numbers though.

Welcome to ecomodder!

while i have no grill block experience, i can say that all of the fords i have come across, (with auto tranny), have the cooler integrated into the lower portion of the radiator. look under the hood and follow your transmission lines in and out of the radiator. i'll bet they run in a similar fashion to what i described above.

i transmission temp gauge is also relatively easy to install, for extra peace of mind.