Might try Raybestos, Wagner and what ever happened to EIC? At least with these,
when the castings are made in china, they hold their suppliers to a higher standard
of quality. The W/C I've purchased from NAPA were fine, no issues.
I found 2 Wagner NOS rear cylinders, but had to pay about double for them.
The Chinese rear cylinders have some problems,but the front ones seem ok.
If you want USA you have to look for NOS.