Ok, one more question on the Holley jetting.

The more I think about it, I don't see how the AFR could ever be constant or leaning out (before the mains come in) with a big cam. Idle AFR set with the needle screws wherever it likes, as long as there's enough range, ok.

But as Mattax said, AFR richens as the vacuum rises off idle from the 7-8" idle vac, sucking harder on the t-slot and the t-slot provides more fuel from the bottom of the slot (and less air bleed at the top of the slot too).

Seems like it will be a compromise at best. If I make the AFR right with the full t-slot feeding, won't it be way too lean just off-idle, which will cause a lean stumble?

Edit: yes, I have a pin vise although I haven't tried your exact method yet.