Assuming they're the same thread, either would likely "work ok" I assume. But the first one with the extended siphon tube is original equipment on at least the earlier Broncos. At some point Ford did start using a curved-tube elbow with a higher lift, but don't remember for sure if EB's got them or just full-size trucks.
Either way, the first one is the most common in my experience.
Never heard 100% why the siphon tube design, but it likely was felt it had a positive effect on either flow, or consistent temperatures pulling coolant from lower near the surface of the coolant passage.
It's also semi-sacrificial. Whether designed that way or not, the extension tube is usually the first to rust away into nothing.
Paul
