What tune for the 6.4? Eric will get you in mid 12s on just a tune
Most tuned 6.4's get in the 12's with a crew cab 4x4
. The only 14sec 6.4 i've seen still had the DPF intact. Duramaxes on the other hand really need that tranny rebuild right off the bat, and a lift pump, and some tierod sleeves, when the Ford can beat on the stock tranny for quite a few miles.
2005 F-250 FX4 CC SB
EGR delete, ARP studs
Spearco, AFE, Flowpro 4"
Suncoast tranny (want a NADP)