I would contact Hirsch. I didn't have any luck trying to maneuver on his website. The next engine paint that I buy will be from him, I am tired of the auto store crap that takes 2 cans to cover an engine block.
Good luck to you.
Luckily, I've got a couple really good paint supply shops in my town. I've also got a couple engines I'll be painting. One of the shops will be able to mix me up some good catalyzed urethane.