I thought I'd share these papers with you guys. I found these useful.
SAE 670067 - Mark II - 427 GT Engine Induction System
Has details of the early Ford flow testing setup.
SAE 720214 - Design Refinement of Induction and Exhaust Systems Using Steady-State Flow Bench Techniques
Paper describing the AMC flow testing setup and calculating port flow coefficient.
The Flow of Air Through Circular Orifices In Thin Plates
Useful info on discharge coefficients etc. with respect to having the orifice in a wooden box (Durley box).
The Flow of Air Through Circular Orifices With Rounded Approach
Discharge coefficients of orifices with rounded entrys.