Unported head quickness?

My 68 dart GTS ran best of 12.98@105, 68 340 with stock replacement TRW pistons, 9.5-1, stock X heads, MP 508/280 solid circle track cam, 238@50, around 480 lift after lash. Air Gap intake, 750 Holley DP with proform main body, flow tech headers uncapped, 727 with unknown 3800 stall converter, 410 rear with 235/60-15 BFG drag radials. Has SS springs and Competition engineering drag shocks all around, FBO ignition and a MP dizzy that I set up.