Timing using LS1 edit

I have a question about adjusting timing on an LS1. One of the columns in the LS1 edit has to do with Airflow per cylinder, however dividing the air flow from the MAF by 8 has nowhere near the value in the table. The Airflow is based on load, how do you calculate the load? I don't have an LS1, but I was trying to help a friend tune, and I couldn't even begin to tell him where in the timing chart to start modifying because I had no way of telling the individual cylinder flows (loads) as the RPM's go up. Can someone give me the heads up? Is there an equation to use to figure this out? BTW he scans with AutoTap.

Bill