When doing comparative testing, it is imperative to use the same radius inlet guide (not rolled up clay method) as the specific entry has influence on results. On the exhaust side, one should always use a short length of pipe for the same reason.
The methodology of area under the curve is best evaluated by graphics and using the cfm/sq in rating. One should have a graph of the cam / valve lift for that evaluation as well. It is in these types of details that gains are sqeezed out of otherwise run of the mill components.
After the heads are evaluated, then one can begin sorting out manifolds and carbs and placement of same.
Notes, lots of notes so you can take a look at what items worked the best. This is particularly important when you are evaluating valve jobs.
Lots of patience, study, and thoughts with coffee will help get the job done.
Regards,
HB2

Dissident