Missed on this combo?
I think the trick to this would be the head flow #'s at high lift.
Your Dyno pull peaks about 700 RPM early for what the rest of your combo looks like to me. If it sustained head flow through the .668 lift of your cam, I'd think it'd keep pulling, and hit your numbers.
is the .668 with the 1.6 rockers factored in?
I have seen many "race heads" that popping a big 2.08 or 2.1 valve into actually shrouds the head flow on a 4.030 bore. thus actually hurting top end...ask me how i know.lol