Ever since the rebuild I have had the same issue of this annoying hesitation. I have a 306 with an E-cam and ported e7t heads, and a ported stock intake. The car idles great, has tons of rubber smoking torque, and drives great when crusing at highway speeds. The problem is that when acccelerating from a dead stop as your speed increases the engine slowly, right around 50 MPH starts to feel like it is running slower, almost like the timing is getting retarded, then you have to give it just a little more pedal for it to pick back up and start to accelerate again. Its like this everytime, even when cold. I have 19 lb injectors but do not know what my fuel pressure is at. I have not changed anything except add a CAI with the idle spacer plate from Ford. Any suggestions?