I've been looking for a cowl hood - metal or 'glass - for over a half year now with no luck, seems like the pre 92's have fallen off the aftermarket radar.
The only other alternative I've come up with is a company out of South Dakota that makes metal cowl scoops you can weld onto a hood. I have an '88 and just installed a 'glass cowl scoop, I wanted to make sure I was happy with the look and function before I shell out the bones for a metal scoop $$$.
If you're interested I can dig up the URL for the company that makes the metal cowl scoops, when i repaint this spring that is the way I'm going to do it.
If you find anything else please keep me posted, it would be sooooo much easier to just bolt a hood on.