Is anyone aware of a "Hi-output" or upgraded motor or squirrel cage for for the stock unit on an '84, 8 cyl., AC car?

I would like to know this too. The blower on my 78 sucks. There as got to be a better one out there.

No hi-po blower motors for our cars. Your best course of action is a "new" A/C Delco replacement motor and replace the red wire to high blower relay with new to assure a full 12 volts to relay and blower. Weak motors, old wiring and relays are the biggest flow problems we have coupled with poor designed ventilation system. You might also check that your distribution case is sealed and no leaking air flow. Check out this article:
http://elcaminocentral.com/article-category-1.html