No. There is a special build of Glide64 somewhere that forces this stuff, because you are not the only one who has asked this.
You cannot disable hardware stretching, and no plugin apart from the special case I mentioned earlier (AFAIK) has such an option that you ask for. Apparently this is very difficult to do because of the way the N64 hardware works, and the Glide64 build is just a quick and dirty hack, or so I've heard.