[ERA Chas]

John,
Forget the rod-that's not what you're asking about. It's ERA's bracket that Pat shows.
Get one from Bob.
Don't sheet-metal screw it to the cowl. If you use speed, it will slowly egg-shape the holes and pull out.
Mock the bracket in place using masking tape. Remove windshield. Using a long (at least 4" bit) drill two mounting holes in the cowl, straight through the second wall of the cowl. Then from below (the back side of the cowl) install 2 1/2" long (or longer if needed) hex machine screws which will protrude from the cowl. Trim them to be just tall enough for the bracket thickness and nylock nuts on top. Snug down the bracket.
If you just parade the car, snug the windshield frame legs into the chassis mounts and do without the bracket.
This is what I did with my early chassis car-don't know if the cowl structure changed in your later car. The glass is too thick there to just install nutcerts from the top so that's why I through-bolted it.