Looking at my question again, it is poorly worded. What I meant to ask is "Have you checked and/or measured lift loss due to pushrod deflection?"
It just seems to me that the long, skinny pushrod is more likely to bend than the beefy short rocker arm, even with the addition forces.
Thanks again for the work you are doing. I've bought your book and it is a great resource, even for an A-Body guy like me.