They could be handy for a new engine break-in if you had dots painted on the pushrods to verify rotation. You would only need to see them all turn at first start, oil would be clean.
Clear plastic valve covers are like communism; they look okay in theory, but fail in practical application.
Just seen this 32 pontiac on marketplace with a video of a running engine with them on it for your viewing pleasure https://www.facebook.com/share/17huMWAQjC/?mibextid=kL3p88 .
The Jalopy Journal
