I buy Chevy Corvette FI cast aluminum water necks on eBay for $20-$30.They don't leak. The Chinese chrome steel ones rot through in no time. Like everything else, you get what you pay for. Believe it or not, I called a local Chevy dealer who has a performance parts section and asked if they had any water necks that were not made in China. Nope, all they had were Chinese junk.
I got the part number from a post you did. I couldn't find the thread, so I did a SEARCH and posted on this thread. The thanks go to you.