hi, don't know 100%, but 99% sure they are chinese castings, since Carter has been out of business for over 20, (30?) years. This is not a bad thing in and off itself, but as usual, caveat emptor. The Carter BBD is, believe it or not, a very popular carb, a LOT of Mopars used them, and, as the AMC version, are widely available on ebay. The line to look for is, "US Stock", or, "shipped from US". Occasionally you will find a genuine Carter on ebay, either rebuilt or NOS, and the prices reflect that. Personally, on my "no expense spared", 84 Eagle restification, I challenged myself, and went with the original Carter BBD that came with the car, rebuilt/overhauled of course, (twice!). Took me about a year, educating myself, chasing down all these sensors (8 of them!, six of which are still available new. if you know what to ask for, and where to look.) But, this Eagle now ROCKS!
If your car already has the ECM Test bypass, as I believe it does, you do not need the electronic BBD. Look for a 77-80 NON electronic BBD, came on Hornets, Concords, Spirits, etc, even the 80 Eagle, and If I recall, you already have a DUI, right? You are halfway there. I am sorry you are not having any luck with the 2150. I ran one for over 16 years on Eagle #1, with not a SINGLE problem, still have it, though it needs shaft rebushed now. Once I set it in 1999, I NEVER TOUCHED IT AGAIN!. it was that good, but this was a genuine Motorcraft I pulled off an AMC 304 years ago and rebuilt myself, these carbs are still available, though getting worn out now, and may be an option for you. I have about 4 cores in my shed, repeat, CORES, and you are welcome to one if you want, they all need to be torn down and rebuilt, and i make no guarantees, but, again, you are welcome to one if you want, just give me a couple of bucks for shipping. Hey, beat THAT price!
Again, I am a fan of the BBD, they are NOT a problematic carb, they just need someone that understands them, and isn't willy-nilly pulling stuff off to "improve" performance/aesthetics, etc.
The Carter BBD, and it's 1bbl cousin, the YF, were the LAST line of carbs used by the major American car companies, all the way to 1992, and maybe even a little later in the Ford F150/300cid six. So, they HAD to be ok on some level!
I am also a fan of the 2150, so, I am a happy man!
good luck, gz