Most well-behaved servers will only send chunked-encoding if the client claimed to be HTTP/1.1. If the client is HTTP/1.0 it will fall back to doing "Connection: close"

The only big thing chunked-encoding gives you is the ability to do a keep-alive connection when the server doesn't know the Content-Length in advance. (Technically it also added "trailers" for sending headers after the reply body, but that's little-used)