The 5x7 sealed beam unit that was an option on the Econolines is one of the most common (if not
the most common, certainly in the last several decades) headlights in the world. I own 3 cars that use them, and my Econoline is not one of them (Subaru XT6, Toyota 4Runner, and Toyota Celica). There are H4 conversion housings, dedicated LED, dedicated projector, etc. options everywhere.
That said, I have some mediocre, plastic lense H4 conversions in my 4Runner. Pilot brand, IIRC. They're mediocre, optics are acceptable (the little street driving done with it, I haven't had anyone flash their high beams at me), but only a bit better lighting than a new sealed beam.
I have some terrifyingly cheap Chinese LED units in my XT6, they're fantastic, as long as you don't mind the fact that nobody around you can see. I traded them for a 6-pack of beer when he removed them from his MR2 because the optics are so bad. But my XT6 is only used for Rallycross and ice racing, and gets towed to those events.
I'm torn what to use on my Celica (which is actually daily driven in the summer months, so needs to have decent lights). Hella E-code (European street legal, cast even less light above the cutoff than DOT) lights with halogen H4 bulbs are a tried-and-true option for 10+ years, and IIRC are about $100 for a pair of housings, another $20ish for some bulbs. Truck-lite LEDs are the proven LED option over the last 5 years or so, but they're very expensive ($400, I think that's for a pair). There are hundreds of
cheap LED options out there, but there are more and more decent ones for more reasonable money. Auxbeam just came out with some that have me tempted:
https://www.auxbeam.com/driving-light/7-inch-driving-light/spu00143
You can also convert to the halogen composite lights (the trapezoidal ones) found on the nicer trim levels. But IMHO the only acceptable housings are OEM, the aftermarket ones that I've seen have considerably inferior optics. Although they do look better.
It's also possible to convert to the '08+ headlight setup, but you also need fenders, hood, grill, and probably some mounting parts, too.