I was reading in Andy F's book on stroking the big block mopar about port cross sectional area and that it largely determines where the torque peak will sit. I think its the Mcpherson formula. I was just reading a book Practical Engine Airflow (very good book) and it goes into that as well as port velocity etc a lot as well.
I had always thought of the camshaft setting the torque peak rpm but my take away is that the camshaft can broaden the torque curve and therefore extend the peak...
Port Cross Section and Torque Peak RPM
