8 3/4 pro gear

You are right. Missed that one word, however, I'd call both manufacturers and ask if they make them.[/QUOTE
We did call Mark Williams (after I had posted the question) and he said no one that he knew of made any anymore. They did give us a suggestion of putting a set of standard gears in an oven to take the heat treatment out. (I don't recall the degrees or time, as the car owner is who talked to them) They said it wasn't quite the same as a pro gear, but would be an improvement over standard gear as far as reducing the brittleness.
Heat the gears to take out the heat treatment, huh? Some say cryo them to make them stronger. I'd ask one of the gear manufacturers for the Rockwell hardness of a pro gear, then have a reputable machinist check the hardness of your "re-heated" standard gears to see if you get close to that Rockwell number. There are some good shock proof gear oils out there that can help brittle gears live longer. Logic says a brittle gear will have less drag that a soft gear, but yes, they have to hold up to the task. Feel free to ignore everything I just typed here.