There are plenty of foundries in the US that cast heads. I get my heads cast at a local foundry, I met another foundry at PRI that does some work for TrickFlow, Dart gets their heads cast at a foundry in Wisconsin, last I checked Buddy Bar is still around and they cast heads and intakes, etc. etc. etc. The problem is that the foundry business is a huge mess right now. First Covid hit, demand for casting products dried up, and all the manufacturers that buy from the foundries cancelled their orders. (The same thing happened in automotive electronics by the way, as many of us know). Then, demand bounced back far faster than anyone expected, but with the $600 per week stimulus check package, for many foundry employees it made more sense to stay home and collect that, rather than go back to work. So, the foundries were short staffed, with a big glut of orders. The manufacturers that provide raw materials, like aluminum ingots for casting, were in the same boat, so there was a shortage of casting materials. Lead times stretched way out as a result, and the biggest customers are always going to get their parts first, leaving smaller markets like automotive aftermarket to wait. Even now, the employees are not returning to the foundries very fast, because hourly rates have gone up so much that better jobs are available at the same wage. After all, a foundry is a tough place to work; it is hot, loud, and dirty, with sand everywhere. So if the foundry I use is any indicator, the foundry business in general is still understaffed, and they have to pay more to retain their employees.
Things are beginning to loosen up now, at least at the foundry that I use, and they may be more or less back to normal in 6 months or so. But I still have product there that I ordered at the beginning of March, that has not been delivered. I've gone to the extreme of looking for other foundries that can cast my parts, but all the ones I've talked to locally are not even accepting new customers; they are concentrating on delivering to the customers that they have.
So, lead times are still extended, and prices will be going up due to higher wages and higher raw materials costs. Pretty much all we can do is deal with it...