value of porting

How high is the value of porting at 5500 rpm? i understand that AMC V8 heads have very good flow(for factory heads) but are they good at low levels of lift (.2"and lower) i understand that this is where the gain is to be made on most engines. i am not talking about increasing the runner volume by much just cleaning it up nearest the valve because most engines have most of the resistance in that area? i have seen gains of 30 horse on a 5.0L ford with no other modifications just through this, can somthing similar be expected from a 360?

would any head work be recompended at this RPM?

CC
Yes you can gain flow on AMC heads with a 'clean-up' as you stated. The closer you get to the valve, the more important port shape becomes. You need to decide if your staying with a 30 degree seat or go to a 45 degree seat. 30 degrees tend to help 'low lift' port flow. You stated you wanted good flow at .20" of lift, stay with 30 degree intake seat angle, IMO. Your intake flow at 5500 rpm with suffer minimally, vs 45 degree seat angle. Backcut the intake valves at 20 degree. Have your intake seats ground to; 30 with a 40 degree top cut and a 20 degree bottom cut. The bottom cut will have to be machined. A stone of that angle will more than likely try and 'wedge' itself into the port throat and explode. I'm sure others will post their views and suggestions also.
Larry