Anyone ever cut a vented "heat extractor" fiberglass hood?

If you locate your vents (or even scoops I imagine) near the front of the hood (but behind radiator), the low pressure area formed by air coming up off the grill area helps draw from the engine compartment. Look at 1998 5.9 Grand Cherokees. The hood vents were air extractors, and the fan shroud had 1 way flaps to allow more air to pass through the radiator when in motion (more than the fan would move on its own), but they returned closed when sitting still, so the fan could draw.