Unported head quickness?

Junkyard LA short block + unported EQ magnum heads 2.02/1.625 + 224/230 .513" cam = 12.91 @ 105.6 MPH

The other parts in the "Pile":
MP M1 dual plane intake
1/2" 4 hole plastic spacer
Holley 3310 Vac Secondary carb (white spring in secondary, stock jetting)
Summit Racing 1 5/8" headers
Summit Racing 2 1/2" duals to the back bumper (no crossover)

904 with DIY shift kit
3200 Stall Edge Racing converter

8 3/4 with sure grip and 3.91 gears
255R-17 Riken Raptors on 17x8 rim

All steel 67 Dart running at a race weight of 3450lbs