Come on Edelbrock. Get your act together.

The "TL/DR" version of what follows: An independent foundry cranking out crap like that would not be around long regardless of location. Casting is a cut-throat business.

Long version: Sand casting is a fickle process. Sand is always going to be at least somewhat problematic just by its nature. A foundry needs to be run/supervised by a foundry guy--someone who's worked in the process and knows how to recognize problems and their causes. Owning the foundry is a double-edged sword: "Strict quality control" can very easily become "we only have to make ourselves happy."
That port with the huge intrusion was made by a core, which uses specially-treated sand that needs to be replaced fairly often. The sand in that particular core may have past its useful life for core work. Some fell out of the core prior to pouring and that's the result. Some of the uneven ports were probably caused by someone "fixing" sand loss by hand-smoothing cores--something every core guy does at some point. The rest of it looks like core shift, which tells me the patterns need attention. They're worn and aren't aligning properly (or the person setting cores needs a smack upside the head). Core shift is inevitable to some extent, but it shouldn't be that bad. I saw a lot of seemingly-OK castings get scrapped after machining.
Another problem is the fact that their machining center is apparently separate from the casting facility. The open end of that badly-intruded port may have looked OK fresh out of the mold, but once that surface got machined the flaw was right at the gasket surface. Does the guy running the machine even know to look for casting flaws? Probably not. "The guys at the foundry said it was fine. Run it."
At both foundries that employed me lifetimes ago, we did just enough machining and measuring on-site to know whether a part should be shipped for final machining. A simple test jig can save your butt from dozens or hundreds of flawed parts. Everyone along the line knew how to recognize a bad casting, and parts got scrapped at every stage of production. A 20% scrap rate was considered normal--one out of every five castings was garbage--for iron. The aluminum scrap rate was 10-15% higher. We were always looking to reduce that, but not at the cost of quality. Close enough, wasn't.
Hilariously enough, a lot of the in-process scrapping wasn't the result of some heartfelt dedication to quality--it was pure spite. "Screw the rich bastards in the office" wasn't an unusual attitude, and a lot of guys would gleefully condemn a potentially-OK-after-machining part for that reason alone. It was rarely questioned, too--better to scrap two good ones than send out one bad one.
Pattern-making and maintenance are expensive. Taking a pattern out of production to repair it means lost dollars. Well-run foundries have multiple patterns for the same mold. The pattern is rotated out after X number of copes/drags/cores for measurement, inspection, and repair. The "dash number" after the displacement in your block casting? That's the pattern number. If they had a bad batch of 2780930-340-6 blocks, they would have reason to suspect something was amiss with the #6 pattern. On Mopar blocks, I've seen pattern numbers as high as 10. Is Edelbrock doing this? I don't know, but it appears to me that "production, production, production" is pushing their foundry to add less "green sand" to the cope & drag line, run their core sand too long, and not properly maintain their patterns. Is that the foundry's fault, or are they simply trying to meet unrealistic demands from corporate? You'd almost have to work there to know.
I don't think it's a "country of origin" problem, I think it's a "quantity over quality" issue. Whomever owns Edelbrock now (it looks like IOP sold Edelbrock) probably has shareholders. Few things can affect quality quite like a stock IPO. A large group of people demanding ever-more return on their investment is a lot of pressure. You can make 'em happy two ways: Increase your prices or cut your costs (and eventually corners).

I can't speak to the overall quality since I've not measured or test-fitted yet, but my still-in-the-box Speedmaster heads look like much nicer castings than either of my NOS Six Pack intakes (340 & 440). After seeing these photos I'll give the Victor W-2 a much closer inspection prior to using it. The Strip Dominator it's replacing was a gem.