I had a stock (rules required) airtex mech pump on a circle track 360 (9:1CR, 2bbl) with 5/16 line & there was NO delivery issue at WOT at 6300 RPM at the end of the straights. I'd sure think a DP holley would not have inadequate needle/seat sizes. Stay on this & keep us updated as we are anxiously awaiting the outcome