I'll play devils advocate for a moment. The factory air boxes do a great job of keeping the air cool. But wow are they restrictive! They usually have a very small inlet.
Is a lot of warm air better than a limited amount of cool air? The massive air leaks into and out of our engine compartments is pretty high. Next time I'm logging data I am going to see what my AIT is with my boring open element K&N hanging off the throttle body.
Ding, ding, ding...winner! That is why I went with a factory air box that could be modified to allow more air coming in. There is nothing "Cold Air Intake" about any of the open type K&N filter in the engine compartment setups. They're sucking up that hot air under the hood.
Spend some time looking at different factory box setups and there are a few out there that can be modified to flow adequate air for any realistic Bronco power plant. The advantage to a factory air box is some/most have mounting provisions for the MAF and calm/quiet the air down as it enters the intake tract, vs. having to build a shield to keep fan wash away. YMMV....