My view is a little different. Looking at the incrementals it was quicker everywhere except the 60ft. The fact that its was able to do that with 5.5 inches of vacuum tells me that engine needs vacuum to aid it in the vaporization department as he's running pump fuel which has higher temp fractions. I've seen 4 inches of vacuum at the top end take off 4 tenths and 5 MPH on a combo that didn't open the secondary's due to a linkage issue.. Not so this car so there's more in play than simple airflow. For me its a good example of the chemistry involved in combustion.
Having to fatten up an engine could be viewed as needing more of the lighter fractions of the fuel blend to help out the burn as they vaporize much easier because there isn't enough vaporization taking place in the intake tract and on the compression stroke to gas the liquid sufficiently.