Thanks for all of the good input guys.

I'll do some testing to rule out fuel and ignition. Don't have any way to log data.
I was hoping someone had success with adding 20# with some shims and calling it a day. I guess nothing's that easy (although I did cure a similar issue that way with a W-2 stroker motor, but it had TONS of installed height to work with).

If I had to build this one again, I'd probably skip the roller set-up and just go with a flat tappet... more cam choices (street) and would save a LOT of $ and a lot of pushrod clearancing work, etc.