I'm pretty sure there is a thread around here somewhere that explains how to extract the hot air from behind the radiator without using heat extractors in the hood. Can one of you kind fellows help me find this thread?
I just about did the same thing, however I figured out that the air also has to pass through the fender liner. I ended up drilling 1/4" weeping holes in the floor of the cavity. I drilled about 25 of them in an X pattern so as not to weaken the panel. It worked fine.